This achievement is awarded after completing the following missions in Sequence 8 - The End of an Era with at least 50% synchronization:
Memory 1 - Discovery
Memory 2 - The Exchange
Memory 3 - End of the Road
For those of you going for
there are some videos posted below that should help you achieve 100% synchronization in each memory. The videos do not belong to me and I do not take credit for them.