Swapping Gift

I got a junk letter with instructions on how to retrieve come gift, which consist of 3 parts. It sounds too good to be true. The meeting place is at nite in front of rows of houses. Plenty of gifts to go around, recipes, electronic kits, food. Naturally I grab one of the kit. I still don’t believe it is for nothing. But then realised that I might had to put something back in return.