We tell him the same thing we told Dez.

[That Vault-Tec moved Riley into another vault, replaced him with a lookalike. They found the vault records and tracked the vault down to the coast. It was flooding, but they got there in time to find Riley's cryopod.]

I don't like lying to him, [Riley says softly.]

We don't have much choice. It's not like he'd believe us if we told him the truth.