Throughout the run of the British youth-group Round Table reinterpretation Merlin, the titular young wizard has struggled to keep the secret of his powers. In tomorrow night’s season finale, though, Merlin faces off against duplicitous, traitorous Agravaine. As revealed in this exclusive clip, the showdown doesn’t exactly turn out the way Agravaine was expecting. Watch the clip:

The season 4 finale, which features fire-breathing dragons, a sword in the stone… and a long-overdue coronation, airs Friday at 10 p.m. ET on Syfy.

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