What is the summary to rangers apprentice and the icebound land?

In "Ranger's Apprentice: The Icebound Land," the third book in the series by John Flanagan, the protagonist Will and his friend Evanlyn find themselves captured by the ruthless Skandians. As they navigate the treacherous icebound landscapes, they must rely on their skills and wit to escape. Meanwhile, Halt and Horace work to rescue them, facing their own challenges and adversaries. The story highlights themes of friendship, bravery, and the struggle against overwhelming odds.