Requiem of the Rose King - Season 1 Episode 21
It should still be in time now.

Buckingham, determined to rebel, tries to win the cooperation of Bishop Ely and Stanley. Meanwhile, Richmond advises his father-in-law Stanley of the conditions under which he will join the rebellion. Those conditions: The death of King Edward V and his brother, who are imprisoned in the Tower of London. Buckingham believes Richard III, and no one else, must commit the murders. At the same time, Richard enters York and waits for Buckingham, who is expected to come. However, after the coronation, Richard is visited by the assassin Tyrell.