Spoilers----

 At the end of the book, Hauser tells Tom to lay the pack with the Codex in it on the bridge and he does. Then all the Broadbents walk away towards the cliff. Then the bridge explodes, Hauser dies, and it's assumed that the Codex also falls into the ravine.  But then later Max supposedly gives the Codex to Tom and Sally.  How did they get it?? There's no mention if Tom hid it in his shorts, he grabbed it on his way off the bridge, nothing. So how did they get the Codex if it fell into the ravine??  I mean, the ENTIRE book is a race for the Codex, and it's the biggest plot hole in the entire novel!!  Help!