THREATS — Kane’s (Henry Ian Cusick) attempt to prove himself useful tests Wonkru’s allegiance to Octavia (Marie Avgeropoulos). Madi (guest star Lola Flannery “Shadowhunters,” “Home Again”) faces an unexpected threat inside Wonkru, forcing Clarke (Eliza Taylor) to make an unlikely ally. Bob Morley, Paige Turco, Lindsey Morgan, Richard Harmon, Chris Larkin and Tasya Teles also star. Michael Blundell directed the episode written by Drew Lindo (#506). Original airdate 6/5/2018.