Can someone summarize this for me? It's rather hard to understand because there's a lot of communication.

And Gawayne rubbed his arms, his chest he beat, Then grasped the battle-axe and braced his feet, And swung the ponderous weapon high in air, And brought it down like lightning, fair and square Upon the stranger's neck. The axe flashed through, Cutting the Green Knight cleanly right in two ,And split the hard stone floor like kindling wood. The head dropped off; out gushed the thick, hot blood Like—I can't find the simile I want, But let us say a flood of crême de menthe! And then the warriors standing round about Sent up from fifty throats a mighty shout, As when o'er blood-sprent fields the long cheers roll Cacophonous, for him who kicks a goal. "O Gawayne! Well done, Gawayne!" they all cried; But straight the tumult and the shouting died ,And deadly pallor overspread each face, For the knight's body stood up in its place And stepping nimbly forward seized the head That lay still on the hearth-stone, seeming dead; Then vaulted lightly, with a careless air, Back to the saddle of his grass-green mare. He held the head up, and behold! it spoke. "My best congratulations on that stroke, Sir Gawayne; it was delicately done! Our merry little jest is well begun, But look you fail me not this day next year! At the Green Chapel by the Murmuring Mere I will await you when the sun sinks low, And pay you back full measure, blow for blow! "He wheeled about, the doors flew wide once more, The mare's hoofs struck green sparkles from the floor, And with a whirring flash of emerald light Both horse and rider vanished in the night.