You have to solve the magic boxes,and solve the cairn.
There is no cheat in any mission in any 39 clues game!
mission 7 39 clues answer for here lies b. fore e . fines
arctic
On a bookshelf at the top
yep
At step 11, just put the hook at 39 degrees and 28%. On step 5, fit the pieces together. At step 7, the answer is his tomb.
Boxes on Beechey Isle
456
good
Arctic is the code you have to type in.
Near the bookcase on the right.
there is no magic box