Story related and cannot be missed. Just simply play the game.
There are 6 memories in DNA Sequence 4.
Memory 1 - Practice What You Preach
Memory 2 - Fox Hunt
Memory 3 - See You There
Memory 4 - Novella's Secret
Memory 5 - Wolves in Sheep's Clothing
Memory 6 - Farewell Francesco
After you complete the last memory the achievement will unlock.