He wasn’t alone. College student Otto Warmbier may have arrived home on Tuesday, but three fellow Americans are still imprisoned by Pyongyang. Two of them, Tony Kim and Kim Hak Song, were working at North Korea’s first private university when they were detained this spring. Businessman Kim Dong Chul has been in custody since October 2015 on espionage charges. If there’s any silver lining to Warmbier’s dismal condition — he remains in a coma after allegedly being “brutalized” by his captors — it’s that it could boost efforts to free the others.