separating companions in Mordor question

[blindguardian]

If the Fellowship(with one or more companion) is in Mordor can the card I will go Alone be used?
If yes, how is it resolved?
The player must "kill" a companion instead of separate him? Is it possible?

thanks for the insight!

[Krieghund]

Yes, it can be used. Companions that are separated while the Fellowship is on the Mordor Track are removed from the game.