Return to Its Master (1R224)

[Bombadil]

The event Return to Its Master (1R224) says:
If the Ring-bearer wears The One Ring at the end of a skirmish phase

So, the rings ability must be used to put it in the end of a skirmish, or the event can be played a the end of any skirmish if the ringbearer is already wearing the ring? For example if the ringbearer puts The One Ring, Answer To All Riddles (4R1) during the skirmish, can I play Return to Its Master in the end of that skirmish?

Thanks in advance!

[Elessar's Socks]

End of any skirmish phase if the Ring-bearer is wearing the Ring. So right, it'd work in your example.

[Bombadil]

Thanks!