This is a new idea I just came up with. I'm going to tell you exactly how I constructed the following ciphertext, and your task is to extract the plaintext. If you really want a challenge, you can try attacking the ciphertext just as a string of cryptograms without reading the spoilertag below, but I don't think that will be doable!
Here's what I did to create the ciphertext.
I started with 13 lines of poetry, and applied the Vigenere cipher to each line using the next line as the key (cycling round so that the 1st line is the key for the 13th line).
In case this is unclear, here's a simple example of this encryption method being applied. Plaintext:
Your task is to devise a decryption method to find the plaintext given the above ciphertext. You may use Vigenere software such as this, but brute-forcing by e.g. writing a program to test all the possibilities isn't allowed.