Help pliz (Prince of Persia: The Sands of Time)

Guys this problem I came to 1 boss killed him jumped on beam opened the door for me there catawissa beams with spikes killed me well, I think at CNU with checkpoint and threw me to this door and it is closed well I kakimto miracle spuskalsya were again jumped and the beam which opens the door didn't open and so the EP, what do figs look 3 times a game again took place!