You helped Elijah betray his brother Klaus to help save Elena Gilbert during the ceremony. You knew the Mikaelson family like you knew your own because you were their staunch ally

Only the plan failed at the very last moment. Elijah could not betray his beloved brother.

And now you are a traitor in the eyes of Klaus, whom he will definitely find. Which is what happened today when his people hit you to unconsciousness and you had woken up in the livingroom of the Mikaelson Mansion.