Erica Jong has compared hot-and-sour soup to the heat of an adulterous love. She is undeniably correct, but we prefer to leave the sex metaphors to the poets and just eat it; our lyrically challenged mind can't hope to do justice to its thick, glossy, fungus-y, peppery, eggy, tofu-ey, vinegary splendor. This soup is so good it should be bad for you. OK, maybe it's not exactly health food, but it is low-fat, and there's no question that it confers upon the slurper many therapeutic benefits. Several slurp-worthy hot-and-sours are available around town, but the one at the newly opened In Soo in University City is positively pharmaceutical grade; its mood-enhancing properties are a documented cure for writer's block. The stuff is served so hot that you have to let it sit a few minutes or risk cauterizing your lips, but that will give you plenty of time to vacuum up an order of In Soo's equally excellent potstickers.