Glossary
Ensurance Trap
A situation engineered by the Manipulated Dead that leaves the Living Receiver no choice but to return the Artifact. In the film: the death of Gretchen.
Sparrow's spelling - "Ensurance", not "insurance" - is deliberate: the trap ensures the outcome. Frank's instructions across the 28 days (flood the school, burn Cunningham's house) build the chain that ends with Gretchen killed by Frank's car outside Grandma Death's house. With Gretchen dead and Frank dead by his own hand, Donnie has nothing left in the Tangent Universe and everything to gain by ending it.
Defined in The Philosophy of Time Travel