Her Strong Enchantments Failing

Her strong enchantments failing,
Her towers of fear in wreck,
Her limbecks dried of poisons
And the knife at her neck,

The Queen of air and darkness
Begins to shrill and cry,
`O young man, O my slayer
To-morrow you shall die.'

O Queen of air and darkness
I think 'tis truth you say,
And I shall die to-morrow;
But you shall die to-day.

-Alfred Edward Housman

I've learnt this one too. I'm good at this =)
It a really nice poem, that sounds like a really epic story just finished, with many struggles and dilemmas and a nice heroic sacrifice type thing. It's a bit jarring how the magic woman is killed by a man with a knife, but that's probably not the intention.