The Grounders fought back in the latest episode of The 100 in retaliation for the gun fight at the bridge when Clarke (Eliza Taylor) tried to make peace.
Murphy (Richard Harmon) arrived back at the camp bloody and infected, and it soon transpired that the Grounders had sent him to infect the rest of teenagers. As more and more of them came down with a mysterious virus, Raven (Lindsey Morgan) worked with Finn (Thomas McDonnell) to make a bomb to blow-up the bridge and stop the Grounders from getting to them.
It was a close call but the bridge was successful blown up and Clarke got the virus under control.
Elsewhere there appeared to be no survivors from the ship that came down from the Ark.
The next episode of the season is The Calm. When an accident causes food supplies to run low in camp, Clarke and Finn lead a group on a mission to hunt for provisions but end up in a dangerous situation.
Tune in to E4 at 9pm on Monday to see the episode. Preview it with our gallery below: