Who is the third person?

Please no spoilers for Season 2. I just finished the first season and I think I missed something. When Dylan was woken in his outie's home, who was the third Lumon employee needed to pull off the Overtime operation? Milkshake was with Dylan and he said Mrs. Cowbell didn't know about the Overtime. The only other unsevered employee I can think of is Graner. So who was the third person needed to flip the switches? (Slightly off topic, there is no way Dylan held those switches for as long as he did lol.)