Overlaps slightly with ownage as by all rights should have been a total failure, but since the entire situation was unnecessary I'll post it here.
So we see a UFO, land two hits without bringing it down, it lands before I can send another interceptor and I send in the troops. Its still pretty early so I send in a gunner, an infantry, a medic, and 3 rookies. We land with the UFO to our northwest and a cliff to our west. We grab some meld with no contacts, except some noise off to the side. The noise is always in the same place so I assume there's just one or two packs and the outsider. I decide to move up the cliff, rather than towards the noise, so we'll have the elevation advantage. Once I reach the cliff, I realize that if my troops jump down they can't get back up; the first warning sign. I take a sideways path they can sort of retreat back from, which reveals the UFO. I realize its the medium UFO pattern, despite not passing the first terror mission, second warning sign. I decide to approach the front door without looking down the diagonal/side doors, my normal breach tactic for this type of ship. This reveals that there is a gap greater than most soldier's movement range in front of the door with very sparse cover, the third warning sign, but I ignore it and attempt to advance down this alley towards the front of the ship. My logic is that with the infantry in hard cover with a SCOPE, I have an anchor I can retreat to if an accidental reveal happens.
A rookie to the reveals a pack of 3 sectoids and a drone on the left side of the ship, most of which retreat. With no easy way to engage I retreat as well, sticking to my hard cover and preparing to ambush. Unbeknownst to me because of distracting real life circumstances, this pack also contained a thin man. The thin man and drone circle quickly around make a surprise attack on the right side, where my infantry is. I pop smoke so the squad can shift right into low cover and still fight, then the infantry kills the drone. I also have one rookie circle left so that the sectoids in the center don't get too bold.
To understand my shock, there are two things you must know. One, I have purely conventional weapons, and second rank soldiers. Two, I have not played Long War much, due to the "Long" in its name. So with that out of the way, what happened next was four fucking mutons reveal from behind the thin man. They are in between the squad and evac, with the only escape being the narrow back of the cliff that the mutons thankfully cannot reach.
I write the fight off as hopeless and continue shifting right. Shit immediately goes to hell. The thin man shoots my "sniper" rookie who panics, a sectoid and three mutons suppress various soldiers. I tell my suppressed gunner to counter surpress a specific muton, allowing the infantry to escape. The medic pops smoke again and tries to run as well. The thin man acids a rookie the medic, and an invisible seeker reminding me that oh yeah a while back two seekers revealed. A muton almost kills the infantry. Next turn the gunner and far left rookie get grabbed by seekers, and due to lack of cover I tell the "sniper" rookie to run back out of LoS but stupidly don't tell anyone to overwatch. She predictably dies, but the infantry shoots the seeker off the gunner, who suppresses a muton and allows the medic to escape. The acided rookie gets mindfrayed, making any hope of running away a distant memory. He dies, the gunner dies in a hail of light plasma fire, the rookie to the far left is obviously beyond saving and chokes out. Their sacrifices allow the medic and horribly wounded infantry manage to get over the cliff and sprint back to the skyranger, escaping right before all four mutons get in firing range.
All in all, I managed to get out of the "Long War got hard" moment with only one experienced troop lost. The infantryman isn't going to be back in action for a month but they're such an obviously valuable troop type that I couldn't afford that loss, and I have a backup infantry who can over-exert themselves if I need them to while I get more infantry. What a great class, even if the name is redundant.