Let Sleeping Demons Lie - S2.E20

Sloan is on a jet on his way to San Francisco when they hit bad weather. Derek is on the phone talking to him when he suddenly loses contact and the plane vanishes from the radar. Derek and the team mobilise to find Sloan and the crew, if they survived, somewhere in the middle of a mountain range. Unknown to them one of the items Sloan had with him has released someone orsomething that is now holdong him prisoner.