Neil Sandilands

While Lexa tries to maintain peace and order within the clans, Clarke uncovers a strange and game-changing truth. Meanwhile, a flashback takes us into the darker chapter of humanity's past.

An operation to catch a businessman who is using acts of terror to manipulate the stock market is compromised, forcing the NCIS team to search for new leads.

When a 200-year-old medicine jar shatters in a teenager's palm, she is admitted to the hospital with symptoms closely linked to smallpox; House must make a dangerous decision that puts his life in jeopardy; Wilson and Sam comfort a young patient.

With Barry in the speed force, Iris, Kid Flash, Joe, and Vibe must protect Central City; a powerful armored villain threatens to level the city if the Flash doesn't appear; Cisco decides to break Barry out of the speed force.

In the Season Four finale, Team Flash gets help from a surprising ally in their battle against DeVoe.

Amunet threatens to kill Caitlin if she doesn't help perform a tricky medical task; The Thinker traps The Flash in a speedster-proof prison; Iris is forced to choose whether to save Caitlin or Barry.