'What now' is not a question that takes a lot of thinking for you.
"There's a lich loose down here -"
"There's a lich loose on a lot of levels of the Dungeon," Amy adds, helpfully.
"- and it's evidently active," you finish. "I'd like to know more, preferably without running face-first into it."
"Knowing our luck its phylactery is guarded by being in a room full of horrible shit," River predicts, gloomily.
"Luck?" Darshan scoffs. "That's good tactics."
"Until he needs to move it," you point out.
"...I don't want to admit I'm wrong, and yet..."
"Mmhm. Amy, you're with me, we'll ask around this side. River, you, Lark, and Darshan ask around elsewhere."
"Yessir," River agrees. Lark gives you a grateful look before they split off.
You go for Mike first.
"What's this I hear about a lich?" you ask.
"You must be new. Come in with those soldier boys from the Cornucopia?" he asks.
You shake your head. "Out of the Roost, actually."
"Door's open? I'll be damned, took 'em long enough. Well, here's the skinny. The Lich of the Center came down here some, hell, some four hundred years back? He was already a lich then, mind, so who knows how old he actually is. Had this amulet that killed anyone who wore it and stored the death for later, right?"
"That's worrying," Amy says.
"You're tellin' me," Mike agrees. "Only, he doesn't /do/ anything with it. He claimed this little tiny room, built a throne in it, sat down, and just...sat there. Every now and again he'd get up and ask folks a question or two, usually if someone opened his door, but, y'know, never seemed interested in anybody. Except now he's wandering the Center Ring, pokin' around and askin' folks all kinds of insistent questions."
"Someone steal his amulet?" you ask.
"Doubt it. That'd mean getting in arm's reach of the guy. Nah, somethin' else is wrong. Damned if I know what, though, the guy doesn't have a language in common with just about anyone down here."