and another one.
I really like Dib's hair on here, so I'll stick to that.

I will very much change the text on the pic, but yeah.. (some letters were cut off when I edited the pic)
that's a part of the story in my head

This might contain a few spoilers for a few episodes of the series, so if you haven't seen it all, meh. I'm referencing to some of them in my storyline

yes, that's a PAK on Dib's back...
explanation will follow during the next pics

After the Bologna episode in which Dib and Zim get turned into sausage, they (somehow) managed to find a cure and turn back into their non-sausage-y selves. But, the cure only worked with combining human and irken DNA to overwrite the bologna-caused damage done to their genetic code.
Thus, Zim now has a little part human DNA, Dib a little part irken DNA in his system.
At first, neither of them was very thrilled about that and they agreed to a somewhat peacefull truce until they could find a way to purify their DNA completely.

During the months it took them, a lot of things happened.

Zim found out about his tallest's intentions regarding his "mission" on earth. And that, after all the enthusiasm and energy he put into his work, it was all in vain and just a measure to keep him busy elsewhere.
dejected and lost, he went to the only person that ever really believed in his abilities.
When Dib started spending even more time in his own lab with the strange green kid, his father, Dr. Membrane, finally had enough of his abnormal behaviour and sent him to the crazy house.
Zim was able to free him after a while, due to the surprisingly strong security systen of the facility. They agreed to move in and hide in Zim's underground base and think about what to do with their lost situation.

They came up with a rather wild plan, but with nothing to lose and nothing left to protect except for themselves, the suicidal mission was a very appealing possibility.