"You don't find a highlighted location on a map provided to us inside a cursed painting which has taken us hostage to be slightly ominous?" William queried.
There was a queer-shaped canister in one of Pete's many belt pouches; William tilted it gingerly and held his ear close to determine whether the sloshing sounded more like a consumable, life-supporting beverage of some sort or like liquid salamander fire inside a metal detonation capsule. He judged hopefully that it seemed more like the former. Running out of water or air was not something he'd ever had to worry about, for as long as he'd had a wand. Now it was troublingly present at the forefront of his mind. He wasn't certain they could die in here, but he suspected it, and all the same he would prefer not to take the chance.
"Our creature companion is wearing a belt with pouches as well," William noted, changing his focus to less dark and dire pondering. "Have you looked to see if there are more useful things stored inside those?"