Nineteen Second Encounter maps, mostly rectangular. Shareware.
And then we have Little Shop of Horrors, 19 maps for the Second Encounter by BigDadKupo. There's no storyline this time so we can only guess that the reference to the famous movie was merely a whim. In lieu of a story, the readme instead encourages you to send $2 to the author as shareware fee. If you did, you would get the "mind-boggling" Walls of Enigma scenario, reportedly only for Wolfenstein pros. And if you get stuck, you can always order a hintbook for $5. Since Walls of Enigma is nowhere to be found nowadays, I guess few people took the offer.
===CREDITS===
BigDadKupo