As boring as I found Babel, it was quickly followed by one of the best early episodes of the series, Captive Pursuit. While in the last several episodes, DS9 has seen increased traffic due to the wormhole, this is the first episode in which we encounter life from the other side. First contact, the essence of diplomatic relations.
So what do we learn about life on the other side of the wormhole? The first creature from the other side is an alien who calls himself Tosk. He has some pretty advanced survival techniques, such as the ability to camouflage himself by turning invisible, only requiring 17 minutes of rest per cycle, and has nutrient sacs embedded around his body for sustenance. Tosk is extremely skittish, reacting quickly to unknown noises. He really seems like a fugitive from justice, a cornered rat, with a built-in flight or fight reflex.