In 2151, Captain Jonathan Archer of Enterprise NX-01 tried to convince Commander Charles Tucker III that Starfleet had sent them on a top secret classified mission to a planet to make first contact with a silicon-based lifeform, when Tucker was hallucinating "people coming out of the rock face." Archer told Tucker it was a major breach of security to reveal that information, because T'Pol was the only person granted clearance to speak with them, since they had supposedly made contact with the Vulcans before. (ENT: "Strange New World")