Zeno was a Time Lord who invented a time-based lock called Zeno's paralock. He was rumoured to have built three examples. (PROSE: The Secret in Vault 13)
Behind the scenes[]
Zeno shares the name with Zeno of Elea, a real-world Ancient Greek philosopher. While the Time Lord Zeno invented paralocks, the real-world Zeno is famous for his paradoxes.