Assist... The guy who chopped off Jamie's hand is named Locke. He was a mercenary for the Bolton Family.
As part of the Bolton plans to control the North... Roose & Ramsay send Locke out to kill the remaining male Starks, so they could never challenge the Bolton claim to be the Warden of the North.
Theon/Reek admitted to Ramsay that he never actually killed Bran & Rickon, but he did not know their whereabouts. So the Boltons send Locke to Castle Black. They figured Jon Snow was either hiding Bran & Rickon, or would know where they were hiding. And if Jon didn't have any useful information, then Locke would just kill him & keep it moving.
Locke befriends Jon Snow at Castle Black.
Soon he volunteers to join Jon on a 'stealth mission' to eliminate Karl Tanner and the rest of the fugitives of the Nights Watch who committed muntiny & killed Lord Commander Mormont & took control of Craster's Keep.
During all the commotion... Locke discovers that Bran, Hodor, Meera & Jojen are being held hostage in a cabin not too far away from the main house at Crasters Keep. So he tries to use all the mayhem as a distraction to kill Bran, but Bran wargs into Hodor and uses him to snap Locke's neck. Which ends the Boltons plans to eliminate the remaining Starks.
Assist... The guy who chopped off Jamie's hand is named Locke. He was a mercenary for the Bolton Family.
As part of the Bolton plans to control the North... Roose & Ramsay send Locke out to kill the remaining male Starks, so they could never challenge the Bolton claim to be the Warden of the North.
Theon/Reek admitted to Ramsay that he never actually killed Bran & Rickon, but he did not know their whereabouts. So the Boltons send Locke to Castle Black. They figured Jon Snow was either hiding Bran & Rickon, or would know where they were hiding. And if Jon didn't have any useful information, then Locke would just kill him & keep it moving.
Locke befriends Jon Snow at Castle Black.
Soon he volunteers to join Jon on a 'stealth mission' to eliminate Karl Tanner and the rest of the fugitives of the Nights Watch who committed muntiny & killed Lord Commander Mormont & took control of Craster's Keep.
During all the commotion... Locke discovers that Bran, Hodor, Meera & Jojen are being held hostage in a cabin not too far away from the main house at Crasters Keep. So he tries to use all the mayhem as a distraction to kill Bran, but Bran wargs into Hodor and uses him to snap Locke's neck. Which ends the Boltons plans to eliminate the remaining Starks.
I saw all this shit happen and didn't realize that's how it went down.
Good recap