But on the wedding night, Brangien to conceal the Queen's dishonor and save her from death, took her place in the nuptial couch. The loyal maid sacrificed the purity of her body to her friend, in remorse of the poor watch she had kept at sea, and out of love of Iseult. The darkness of the night hid her trick and her shame from the king.
-The Romance of Tristan and Iseult, atb Joseph Bedier
this is an incredible and emotional display of loyalty by a servant on behalf of her queen. It's such a moving act of love, and it makes me condemn Iseult for later ordering to have Brangien killed and her tongue cut out. Of course Iseult's position is a desperate one, but when someone throws down for you like Brangien did, you owe them that kind of loyalty back. Having them killed is the exact opposite of that. This is probably the bitchiest moment I can think of from any book I've ever read.