I have come to the end of the last ball of yarn, but, as I have suspected for the last twenty rows would be the case, I'm still four to six admittedly fairly narrow inches away from the end of the pattern. Should I ...
Frog most of a ball's worth of work and re-knit with one fewer pattern repeat.
Order an additional ball of yarn, accepting the risk that I will get a different dye lot that is a slightly different color, and the inevitability that I will wind up with most of a ball of useless yarn.
Finish it with that crappy yarn currently inhabiting the dark recesses of my desk drawer. Lime green boucle looks great against dark purply-red alpaca!
Kill myself and everyone else in the building in a gas explosion.
Bind off and give the scarf to my sister as-is. If questioned about the missing corner, demand to know why she doesn't trust me, break a dish, storm out of her house and take a cab home. Later, pretend I don't even knit.