How do you beat mission 8 thirty nine clues

go through briefing and get Ian's message. it says Meet At Roda Island Bridge. when you get to the bridge, talk to Ian and he'll tell you to make an alliance. accept and trust him. then when you get to the place you get trapped. wait a little and a rope will fall. climb up and negotiate for the real location of the book. get to the Ekat Stronghold and do the grappling hook game and then build the robotic dog. then use the dog you built to turn off the lasers and get the book.