If we're going with that plan, then I'd like to propose some amendments:
1. Have a puppet-bird airdrop a snake into the prison, preferably during nighttime.
2. Find an isolated guard. Inject him with the aneasthetic, killing him. Then consume his memories and reanimate his body.
3. Use the guard's memories to determine our target's location and the best way to get a message to her. If the guard doesn't know her location, then we could use the same rat-trick we used at the outpost to find and copy the information. (We can't just go blindly searching every room hoping we come across the right one.)
4. Assume the guard's identity, doing his duties, laughing at jokes he would laugh, talking about things he usually talks about, beating up prisoners, generally act in a way that would not attract attention.
5. During that time, use the best method possible (probably some combination of rat and bird) to drop a note to the woman explaining you are part of the resistance and looking for info. Try to get her to give you the information. If she won't give you the information for free, promise to get her out later, when you can.
6. If she agrees to give you the information, ask her questions regarding her time at the lab, the mass grave, the three projects, and anything to do with Alexander, including where he currently is and why he is being hunted. You will do this through notes if possible, in person as the rat if not.
7. If she is unwilling or unable to act with you, kill her and devour her memories. Make it look like an accident or natural event to avoid suspicion.
8. Using the the rat body, or a human guard body acquired through poisoning with the snake body, you will attempt to discover the standard policies and procedures of the prison, including what they would do to try and track an escaped prisoner. If possible and safe, undermine these operations somehow.
9. Once proper info has been gathered, dispose of any controlled bodies in a non-suspicious way and then telerot back.
To each of those I will also add a general sanity check rule:
0. Consult with Esme to make sure we're not doing anything stupid. For example, maybe it's better to use a snake the bird kills, so that we don't touch the snake at all, in case they can somehow trace it back to us through some sort of residue. Once the guard's memories have been consumed, also use those to judge the feasibility of our next steps.
You consult with Esme about the plan. When you bring up having the bird kill the snake to limit any "residue" she actually seems somewhat taken aback that she didn't think of that. She glances over at the snake she had bought with a look of mild annoyance an shrugs. "Guess I'll throw that in the herpetology section. Killing one on your own is a good idea. I don't know if it will actually work, since regardless of the number of steps you use it always has to lead back to us eventually, but better to at least make it harder for them."
After a few more minutes of working things out, she nods a final time.
"Alright, this seems like a plan. I suggest you leave tonight; when the bird won't be noticed. Follow the train tracks north..." She lays out the path you need to take to make it back to the prison. You spend the remaining time before you leave getting some things set up. You make sure one of the currently unoccupied skeletons in the library responds to your telerot for the purposes of communication with Esme. Then, the both of you head to a different building. Its an abandoned building near the dockyards, a disused warehouse that has been partially destroyed by a bomb blast. Esme tells you it is occasionally used for dead drops. Together you both find an empty metal barrel and roll it over into the partially destroyed section of the building. You jam it into the wreckage in a place where its hidden and then crawl inside and have Esme seal the lid after she hands you a pistol. This location, she decided, is the best place to keep you on short notice. No trace would lead back to the library, and it is highly unlikely that the "enemy" would bomb the same building twice, at least not on purpose. Its imperfect and she says she'll work on getting you a better location for later use of the technique, but for now it will work.
You settle in as best you can, folded into a steel barrel, and project back out to your hawk body, which Esme has deposited away from the Library as well. Around midnight you take flight and follow the tracks as she suggested. You actually stop flying relatively quickly and instead land atop the same train that you and Esme took before, letting its superior speed shuttle you where you need to go in a fraction of the time. Its morning, maybe 6 or 7, when the train arrives and you spend the next hour or so flying out to the checkpoint and then on again, until the prison comes into view.
The prison itself is clearly an older thing; not made by the current regime just taken over by it. It resembles, at first glance, some kind of old castle; A tall stone wall complete with towers and crenelations in the form of an octagon, though not perfectly even as the eastern half slopes partially up the foothils of the mountains around the prison. Beyond that anachronistic wall is the prison itself: it looks almost like a military barracks, with 16 long wards branching off from a central building like the spokes of a wheel. Each ward extends nearly to the outer wall but stops just before reaching it. There are yards between each spoke, with running tracks and other amenities for prisoners on their yard time. You sweep over over the place several times and quickly indentify the central building as not only the guard barracks but also the heart of the prison in general. Its the largest, and tallest of the buildings, a octangular tower rising even higher than the outer walls and bedecked with guard platforms and search lights. For the moment it seems quiet. You pull away and back out to the woods to hunt the snake you need. It takes you a while, but you eventually discover one that suits your needs. You let it bite you a few times as you restrain it, just to make sure it has the all important fangs and then kill it with a careful stab of a talon. The next steps prove maddeningly difficult with your current body, to the point that you actually hunt down a racoon and animate it to get a better pair of hands. Using tools strapped to your hawk body, you carefully cut the snake's head open, inject the deadly concentrated drug cocktail into its venom sacs just as Esme taught you, and then sew it up. Imperfect, but functional. You make a mental note to try and dispose of the snake body somewhere where it won't be found and draw suspicion with its clearly augmented head.
You wait for the next night to come, keeping an eye on the prison and making mental notes about things like guard paths and yard times. As soon as it gets dark and the current shift has ended, you take control of the snake and order the hawk to take you in before coming to perch back in the forest. It drops you off on the roof and you slither down the metal domed roof and into the upper most lookout post. From there you avoid contact with any guards and make your way about until you manage to locate the guard barracks. You squirm silently under beds and about the room, looking for a good candidate; someone sleeping heavily who wouldn't awaken from the bite and who didn't look particularly sociable. You find one in the corner of the room, several beds away from anyone else and snoring loudly. You carefully search for an exposed artery and decide on the neck as it seems most expedient. You line yourself up and bite down as smoothly and quickly as you can manage, sliding the long hollow teeth into the flesh until you feel the throb of the artery against their tips. You then dump your entire supply of anesthetic in a constant stream, making sure not to push enough in at once to be uncomfortable. The man stirs a bit, hand swatting at your head in that half hearted way a sleeping person might shoo a fly. As soon as the drug is dumped you release your grip and slither down under the bed, hiding yourself in case of trouble. You wait for several minutes as the man's breathing grows steadily shallower until it stops all together.
You immediately squirm back up, climb onto his still chest, and begin to devour the memories streaming out of him. You let them wash over you blindly, focusing on none of them for the moment, and then set about animating the body. You use your teeth to drag down a anima connection and tie it all to a ring on his left hand. You have the body swallow the ring and then deanimate it before telerotting into it. You pick the snake up off your new chest and stuff it into your clothing, intent on hiding it away somewhere later. You then close your eyes and begin to go over the memories you stole in detail as you pretend to be asleep. As soon as you give them some attention, the rush up to meet you, like a geyser and nearly sweep you away. This man is older than those young men you killed before; his memories of the past are more hazy in the middle, with childhood and current events standing out the most. You accept the past memories with as much detachment as you can, but you still feel them as though they were you own. You try to pull the important information. What his parents looked like, though they're both now dead, his brothers and sisters, his home town, things that people might ask him about, or that they might know about and bring up. You feel more guilt this time, more melancholy, more sadness at your actions. Are these the feelings those boys you killed would have? Your own? This man's own feelings? You're not sure. You sit on a stump outside your childhood home, arm broken from a trip down the stairs at the school. The sun is setting, its light hidden behind the horizon by a lines of trees on the edge of your property, orange and yellow fall leaves blazing with the backlight. It smells like dust and and you feel some kind of distant nostalgia you cannot place. Its getting chilly but you don't want to go in, not to those stacked boxes and empty rooms. Tomorrow you and your family are leaving this home. You are worried what the future will bring, what you are leaving behind. You don't understand it at all. So you sit there till the sun is gone and you shiver as the starts wink into view. Your mother calls you for dinner and you want to cry, but you just walk sulkily towards the square of lamplight that is the doorway and the half seen shadow silhouette of your mother. You tear yourself away and the scene melts like oil paints in turpentine, softening and flowing away.
Recent events are easier to accept. Banal compared to halcyon memories of the past. You discover his schedule, his routes, the people he talks to and what about. You search his mind for your target but find nothing; she must be in a different ward. You...he knows that political prisoners are kept in A ward, along with the high level offenders, but he doesn't work there. He's on F ward and has only been to A ward a few times as back up for riots or fights that spring up over there. You don't have the clearance to enter the main offices either, not without being summoned there by the warden. You'll need to find a way to do both.
Daylight streams through the windows and you raise yourself up into a sitting position on the bed as the shift change approaches. Most are still asleep right now, but a few men are stirring. You stuff the snake in the steamer chest at the foot of the bed and start getting dressed for the day.