Without whispers, the silencer has no way to contact the mafia. The spy can talk down to the lawyer and silencer during the day, but can they distinguish between the agent and the spy?

The cop's reports are unclear, at least while the miller and lawyer are alive.
TIP: If you're the silencer, don't silence on night 1. Wait for the mafia contact you with names, but be careful of the agent! If you're the spy, don't get lazy. Make sure the silencer knows who you and the lawyer are, and try to make it easy for your subordinates to distinguish your messages from the meddling agent's.