Phin and Miles lift up a grate that has a hidden time capsule underneath. Both forget the combination, Miles thinks back to when he, Phin and Rick were in that same spot. He remembers it to be the Fibonacci sequence. The box opens and it's the reward that Phin and Miles received for their energy converter invention.
Miles is still concerned for Phin he asks her why they lost touch, Phin still refuses to explain, so Miles wants to put an end to the dishonesty between them the next time they see each other.