"To the Death" is a surprising episode because it involves the Federation and Jem'Hadar working together--at least temporarily. It all begins with the Defiant returning to the station--only to find that it's been attacked by Jem'Hadar. However, in pursuing the attackers back through the wormhole, Sisko finds a Jem'Hadar ship-- stricken and on the verge of implosion. The surviving Jem'Hadar soldiers are beamed aboard and that is when they learn that the ones who attacked DS9 are renegades--Jem'Hadar who are independent of their overseers and who COULD take over the entire quadrant. So, to prevent this, the new passengers on the Defiant and the Defiant's crew must work together to stop the renegades.
Much of the show consists of the Federation and Jem'Hadar learning from each other. The Jem'Hadar are clearly super-arrogant and consider humans, Klingons and the like to be wimps--and they cannot understand how these inferior begins could be of any value. Jadzia Dax is surprised to learn how incredibly efficient the Jem'Hadar are. They never sleep, never eat, have no need for procreation or women BUT it comes at a price--they only live to be, at most, about 15!
What follows is good but surprisingly easy. After all, these Jem'Hadar are supposed to be the greatest warriors in the universe and you'd think the battle with the renegades would be a lot tougher! But, given all you learn about this race and the action, this is a very good episode and well worth seeing.