Various Urns exist in the Alien Temple and aboard the Derelict on LV223.

David collects a smaller Urn as the crew first enter the Temple, returning it aboard USCSS Prometheus unbeknownst to the rest of the crew.

Later David examines the contents and administers some of it's contents on Holloway as they share a drink together in the Mess Hall. It starts having a small but definite effect, in the Alien Temple the next day Holloway starts mutating further and as they return aboard Prometheus Vickers burns him stopping any pathogens aboard.

Due to the crew opening the door in the Ampule Room the Urn's contents spilled out and affected small worm like creatures indigenous on LV223, this caused a mutation in them and created a creature called a Hammerpede. A creature capable of regenerating itself, this creature attacked and killed Millburn and Fifield was mutated by the liquid. A mutated Fifield returned aboard Prometheus attacking and killing the crew Ray, Wallace, Taplow and Vladimir.

Other Urns existed aboard the Derelict, held by the Engineers as a form of weapon which they were bringing to Earth, before a release of the contents killed them.