The "current day" portion of the story deals with the Fantastic Four as they deal with the first "watcher" to appear on Earth during the original super-soldier program. After that day, the watcher pillar has stood in a SHIELD warehouse called Project Pegasus. I do appreciate that Agent Wendell Vaughn (Quasar in the Marvel U) is in charge of the project, but he never really gets to do too much in the story. The watcher has a couple lines of dialogue at the end; I assume hinting at the destruction in Ultimatum. I guess the extinction level event that the pillars came to witness was the wave Magneto caused in that other series. So while there is a bit here to satisfy a reader, this mini is more a prequel for Ultimatum than anything else.
Butch Guice has a gritty style that works well on the tech-heavy aspects of the book. The soldiers in WWII look appropriately grizzled and I like his take on the SHIELD uniforms too. The FF don't look quite as young as they should in the Ultimate U, but I'm ok with that.