One Piece.S08E244.Secret Bond! Iceberg and Franky!

Lucci tells Iceburg their hypothesis and has Kaku check his pulse to tell if the things he tells him are true. They suspect that Iceburg's friend from the past, Cutty Flam, is really Franky and it's revealed to be true. Therefore, Franky has the real blueprints. The Strawhat Pirates and Paulie break into the room where they find Iceburg and CP9.