Doctor Pleroma hired two mercenaries to assist the Mad Bomber Roddy Applecreek and the Hundred Hand Wizard Delgal Haberkorn in their exploration of the tomb on the other side of the portal. They needed warriors, so warriors is what he brought: the Cleric Condition Killer and the Fighter La Mal, Threshers from the Grain Cult. He took care of procurement and payment as thanks for the adventurers heeding his wishes and not hiring any of the patients.
Condition Killer explained that the adventurers were welcome to any treasure they found, but they needed to turn over any monster corpses to him and his colleague for dismemberment. Receipts like ears and heads could be claimed for bounty, while other parts could be sold as magical reagents. Roddy filled them and Delgal in on what waited for them on the other side of the portal: Intellect Devourers, Gnolls, alien super-science and maybe even another portal.
As frontline fighters, the Threshers went through the portal first. After a moment on the other side, Condition Killer came back through to give the all clear. The adventurers followed him through into the tomb.