Cullen’s nitroglycerin experiment provides an explosive backdrop for the railroad life in Truckee. Durant’s plan turns deadly.

Cullen and Durant meet with President Grant to discuss the future of the railroad; the Swede puts his plan against the Mormons in action.

Cullen and Mei escort precious cargo through the California wilderness; Eva nurses Louise back to health.

When a polar bear trainer is found dead, Shawn works to prove the bear’s innocence.

Quentin helps Julia with her search; Eliot attempts to win over his people as Margo tries to keep a devastating secret; Penny and Kady become caught between two magical factions.

Dean encounters a surprising message on Bobby’s phone, and Sam and Dean investigate.