The space upstairs from Tanjore, in Harvard Square, has seen a number of Asian restaurants, one after another. So who could tell by looking that Smile would be an excellent, authentic, and even relatively inexpensive Thai place? Certainly not I, but fortunately I followed up the looking by bringing in a large group and tasting all over the menu without finding a hole. As with some Thai menus, dishes are given fanciful names in English. One of my guests, Peter, actually found important coded messages by making sequences out of the odd names: "drunken chicken" ($9.95) leading to "chicken in love" ($9.95) and then to "seafood honeymoon" ($12.95), followed by "seafood dynasty" ($12.95). Those who like their food and secret messages spicier could have "seafood adventure" ($12.95) or "seafood madness" ($12.95). A married crowd, we opted for the "ocean combo" ($12.95).

But first we had fresh rolls ($5.25), golden bags ($5.95), shumai ($5.25), tod mun ($5.25), angle shrimp ($5.25) — always looking for a new angle here — and golden triangles ($4.95). Good thing it wasn’t a Burmese restaurant!

The fresh rolls are the soft Vietnamese "summer rolls," but filled mostly with shredded lettuce and cut into small rounds like sushi rolls. They’re redeemed by their sweet bean-paste sauce. Golden bags are deep-fried purses of stuffed tofu skin, tied at the top; there are three big ones, with an eggy and bland filling that’s very good with the peppery sweet sauce some Thai restaurants describe as "squid sauce."

Shumai appear as seven in the usual sea-scallop size and shape. They are actually wrapped dumplings of shrimp and starch and a little pork, and excellent with a soy dip. Tod mun are usually fish patties with the distinctive flavor of galangal, here upgraded to shrimp, made more numerous (10) and smaller, and served with a fish-sauce-based vinaigrette.

Angle shrimp are probably angel shrimp, tightly wrapped in spring-roll skin and fried crisp to prevent any devilish ideas. Golden triangles, my personal favorite, are curry-flavored potato-in-pastry concoctions, like micro-samosas.

One of the odd features of dining with the Nadeaus is that your comments don’t reach print unless you are very clever, like Peter. Another is that you must order your own food. Otherwise I would order only weird stuff that’s fun to write about. Having my guests pick their own food is the only form of market research I do.

If I didn’t make people order, for example, I would never have tried something like the ocean combo ($12.95), and so would never have found out that the "house plum broth" is actually a thin, lightly sweet and hot sauce that’s ideal with a mixed lot of perfectly cooked seafood (including green New Zealand mussels in the shell). Nor would I have discovered that the salmon fillet is actually the hit of the platter, and that it also comes with lots of vegetables: baby corn, green beans, peas, broccoli. I would have figured, "Seafood in prune juice, phooey."

Instead, every column would be full of notes on "Harvard noodles." These are neither crimson nor thoughtful, but in fact an excellent version of the thick fried noodles called "chow foon" in Cantonese restaurants, topped with bits of shrimp, chicken, tofu, squid, and that old Cantab favorite, Chinese broccoli.

I’d never order beef macadamia ($10.95), nor find out that it has spinach in it. Nor duck pad ped ($12.95), with its Asian basil sauce and surprising vegetables against meaty slices of boned duck breast. I might order green-curry seafood ($11.95) from the matrix of curries, because the complex green curry, buffered with coconut cream, is a favorite of mine, so I always check if it is good (though it never seems to be bad). And I might order pik king ($9.95) to test the red curry that is the other bellwether of Thai kitchens. This version has tofu and vegetables, although it also comes with chicken, pork, beef. Smile makes a good red curry, not blindingly hot, but spicier than the green curry. (The coconut-buffered version of red curry is "choo chee.")

The rice ($1) is Thai jasmine rice, but not exceptionally jasmine. You can also choose brown rice ($1.50), which works quite well with the stronger curries.

An unusual feature of Smile is desserts, although the restaurant has a list of the usual suspects, such as fried banana ($3.95) — fair banana spring rolls, good coconut ice cream — and rambutan ($2.50), which resemble lychees with more pear flavor and less flowery aroma. Cheesecake ($3.25) is surprisingly light and pleasant after a spicy meal; carrot cake ($3.25) is spicy in a British way that also works. There’s also Thai custard ($3.25), which is a somewhat addictive taro soufflé, and sticky coconut rice with mango slices ($4.50).

Décor, as always in Thai restaurants, is rather nice, with handsome art and craft pieces, large embroideries, lace curtains on the windows, and plexiglass over linen on the tables. A cunning mixture of fresh and fake flowers and plants contributes to an airy feeling worth climbing the stairs to reach. Service, despite our large party, was quick and accurate.

Robert Nadeau can be reached at RobtNadeau@aol.com.