This play is set in Illyria
Viola and Sebastian, shipwrecked, are identical twins, apart from unimportant details – e.g. she's a girl, he's a boy. She dresses as boy and in no time has created love triangle with random noble and she-noble, causing tangles when bro turns up. Meanwhile everyone takes the piss out of unlucky Malvolio, who has no apparent function in plot except to be depissed. Everyone else pairs off, end with bunfight.