'Lost'

"Lost," which returns for its fifth season tonight on ABC, is like a troublesome but attractive friend who comes into your house and talks a lot of nonsense that you tolerate because it's entertaining and because you aren't completely sure it is nonsense. It might make sense in some form of the language that you do not personally understand. You can either let this annoy you, or you can try to work out the meaning, or you can just enjoy the flow in a noncommittal way that does not preclude your being stimulated, shocked or held in suspense -- like a fun-house ride.

I am of the third disposition, and have also been of the first. (I wager that even people who love "Lost" a lot more than I do have at times wanted to reach right through the TV screen and give it a good slap.) As to the second, attempting to resolve all its clues, bread crumbs and loose ends into a workable whole is more than my time is worth. More important, it's a drag on the show: The more that the writers find explanations for the myriad strange phenomena that plague the survivors of Oceanic Flight 815 -- the surviving survivors -- the less interesting those phenomena become. The mysterious becomes the merely preposterous. The weirdness of a polar bear on a tropical island is more satisfying than any reason you can provide for it.

Or take the "Valenzetti Equation," the pesky sequence of numbers that pops up everywhere in the series and which has been revealed (via the official Web component) to be the elements of a formula that will predict "the exact number of years and months until humanity extinguishes itself." (Research commissioned by . . . the U.N.!) Well, you just have to look the other way.

Although the series is now headed toward a definite conclusion, a little more than a year away, there is no way that whatever happens from here on in will account for everything that has happened up until now. The writers have been too profligate with the apparitions and coincidences to wrap them up neatly. But more recent mysteries -- how Locke (Terry O'Quinn) wound up in a coffin, for example -- are already being addressed.

These are generally good times for "Lost." After a less than compelling third season, last year's temporal recalibration -- ditching the flashbacks for the flash-forwards -- kicked the engines back into gear. New people with guns arrived. And the whole Kate-Sawyer-Jack thing that once seemed so central to the plot but had grown so tiresome has been, for the moment, put on hold.