Not having the time for any particular amount of subtelty, Heldric simply rips open the mattress - following the sage's instructions - and finds the timepiece within.
"Not far, now hurry!"
The sage makes his way down the stairs with urgency, and Heldric feels compelled to follow. On reaching the ground floor thunder sets the tower shaking, frightening Mr.Whitey (who had come to Heldric on his re-appearance).
"Come now, lightning shouldn't normally strike in snow storms, this is magic at work!"
As he moves down into the basement Heldric is stuck by the subdued but still-present stench of rotting corpses. It is prohibitively cold down here, which would explain why the stench is so closely contained, but also great discomfit to Mr.Whitey. The sage, seeing Heldric's worry, tut tuts - "I'll keep him warm, don't you worry. I am no so helpless as all that. Here now, the entrance to the tunnels are under the bodies on that mound over there."
The mound in question is a small pile of bodies that Heldric can only assume were the chantry's mortal servants and guards before the attack - and are now the chantry's spectres and ghosts. The dead here do not react to Heldric's passage or fearsome presence, but simply wait and stare dully at their surroundings. Images of a defeated past more than souls, really.
Andreas moves the bodies aside with great squeamishness, revealing a trapdoor frozen with blood that he struggles briefly to rip open. It's then that Heldric hears a loud crash coming from upstairs.
The sage frowns.
"It seems they're here. Good luck."