Maryann has had her baby after an easy, pain free pregnancy, of which Jennifer is jealous. Jennifer, desperate to have her baby and end her pregnancy, gets the plan to induce labor by going up in a hot air balloon, but not very high. When they find one, there are two ropes, one that when pulled will release the balloon completely, and one that when pulled will allow the balloon to rise to a low height but remain tethered to the ground, which is what they want. But Larry and Balki can't agree on which rope is which, and an argument ensues, culminating with them simultaneously pulling both ropes.
Larry and Balki [in unison]: Now you've done it. You pulled the wrong rope!
They're found and rescued by a helicopter, but we don't see how they got from the balloon into the copter. It ends with a visual montage of the series' best moments. I didn't realize it was the final episode until that montage. _______ "The sun is shining...but the ice is slippery."