An investigation, ordered by Godunov and carried out by Prince Vasiliy Shuysky, determines that the Tsarevich, while playing with a knife, had an epileptic seizure, fell, and died from a self-inflicted wound to the throat. Source: Internet
The cast also included Anton Sekar-Rozhansky (Pretender), Serafima Selyuk-Roznatovskaya (Marina), Varvara Strakhova (Fyodor), and Vasiliy Shkafer (Shuysky). Source: Internet
He added three scenes (the two Sandomierz scenes and the Kromï Scene), cut one (the scene 'At the Cathedral of Vasiliy the Blessed'), and recomposed another (the Terem Scene). Source: Internet