The plotlines of this issue of Infinite Crisis are as follows:
The opening plotline involves the ongoing plotlin in which involves Batman and the team he has chosen to go into space and disable the Brother Eye satellite. Among these team members is the new Blue Beetle whom it is discovered that the rings of the Green Lanterns appear to be afraid of.
The first minor plotline involves Wonder Woman, and the Earth 1 and Earth 2 Superman talking, resolving issues, and deciding to get back to Earth One to stop Alexander Luthor.
Major plotline number two involves Alexander Luthor's attempts to create a perfect earth and eventually a team led by Nightwing to stop him from doing so. Crucial to this plotline is the disappearance of a major hero/villain and the apparent death of a villain whose been a major player throughout the crisis. This plotline also involves the return of an even more powerful and villainlously confused Superboy Prime and leads to the eventual death of one of our heroes. (Villainously, is that a word?)
After this we witness another minor plotline which involves the mystical heroes proclaiming that they are the Earth's last hope as they summon the Spectre to help them. However, the Spectre appears to want nothing to do with these mystics.
Major plot line number three involves another team which is in deep space and that is led by Donna Troi. This team is attempting to stop the cosmic manipulation going on by the giant hands which they do not know belong to Alexander Luthor. Firestorm creates positive matter and fires it at the antimatter hands. This both stops Alexander Luthor which gives the heroes attempting to stop him on earth extra time to destroy the tower that Luthor is using for his manipulations. Upon destruction of this tower all of the earths appear to collapse into one.
At the end of this issue a hero dies as mentioned earlier in this review. As to the answer of who this hero is you will have to pick up this issue yourself.
The artwork of this issue was between good to excellent and I would give the writing a 8.5 on a scale of 10.