Watch The Boy Behind the Door (2020) HD Full Movie Free on SolarMovie. Watch The Boy Behind the Door (2020) online free. After Bobby and his best friend Kevin are kidnapped and taken to a strange house in the middle of no...After Bobby and his best friend Kevin are kidnapped and taken to a strange house in the middle of nowhere, Bobby manages to escape. But then he hears Kevin's screams for help and realizes he can't leave his friend behind.