John McGuire re-enters in Season 17, Episode 30.
Season 17 fan favorite Johnny Mac hung on for dear life during an endurance comp called "Dizzyland," which pitted him against fellow jury members Shelli Poole, Jackie Ibarra, and Becky Burgess for a second chance to re-enter the house and get his paws on $500k.
The fun-loving dentist was the last juror swinging, which ensured his return to the game, but didn't land him as the week's HOH. That title went to Vanessa Rousso, who promised to keep John safe—for now, at least—if he let go of his rope first.
Watch the full episode where John McGuire returns to the house in Season 17!