There should be no place for a song to hide on one of the most-anticipated albums of the year, but "It's Nice to Have a Friend" still feels like it's huddled up in the farthest, shadowiest corner of Taylor Swift's Lover.

Peeking its head out at track 17 of 18 on Lover -- right before the affirmative conclusion of "Daylight," and just after a three-song run that includes the album's two advance singles, "You Need to Calm Down" and "ME!" -- "Friend" slinks by unassumingly, like the seventh-grader trying to make themselves invisible so they won't get called on in algebra. At 2:30, it's the shortest song on the album -- it's the shortest song on any Taylor Swift album, in fact. And it's not short the way that "Gucci Gang" or "Sunflower" or any number of other late-'10s pop hits are; it's short the way an album interlude is, notable in its brevity, a song that could say more but chooses not to.

But despite these aims at inconspicuousness (or more likely, largely because of them), "It's Nice to Have a Friend" is the most captivating song on Lover. It's the rare Swift song that suggests more than it implies, that punctuates with commas and ellipses rather than exclamation marks and hard periods, and its delicate, crystalline beauty is unlike anything we've heard from Swift before. (Even "Delicate.")

It's also the most unexpected song on the album -- sonically, lyrically and structurally. The production's ghostly combination of choral backing vocals, gently gleaming steel drums and tenderly plucked harps is simultaneously comforting and unsettling, like the final scene of a slasher movie where maybe everything's finally all right, or maybe the knife is coming for the surprise death blow. The short trumpet solo that arrives halfway through feels so out of place on a Taylor Swift album that it's almost comical in its unlikeliness, but it vanishes before its presence becomes flagrant. Most of the songs on Lover end with the sound of Swift's voice, but she bows out of "Friend" with 20 seconds left, letting the harps and spectral ooh-oohs have the last say.

The song itself is not atypical fare for Swift, telling a love story that starts in grade school classrooms and ends with a weekend in bed together -- a romantic arc from childhood to adulthood that echoes "Mary's Song (Oh My My My)," from her 2006 self-titled debut. But "Friend" shifts "Mary's" perspective from a third-person framing -- just 16 at the time of her debut's release, Taylor has since lived enough life to now present such a narrative as her own -- and dials down both the sentimentality and the direct storytelling, instead telling the tale in such intimate time-spanning snapshots ("Video games, you pass me a note," "Light pink sky, up on the roof") that at first it's not entirely obvious what kind of relationship is being described. Even the song's title -- also the closest thing it has to a chorus -- is a red herring of sorts, suggesting a platonic bond that isn't revealed to be more until the second verse's "Something gave you the nerve to touch my hand," a moment that jolts you like static electricity once it finally arrives.

The effect of all of this is to give "Friend" a sense of mystery rarely found in a Taylor Swift love song. Not to say that intrigue doesn't often play a role in her music -- easter-egg hunts and lyrical investigations are a large part of what's bound her fans so closely to her over the years -- but those inquiries have traditionally been into who a song is about, rather than just what it is in the first place. If anything, the one thing that isn't intriguing about "Friend" is who it might be about: Unless she secretly went to middle school with Joe Alwyn or any of her other famous paramours, chances are it's just a song inspired by a flight of fancy, a moment that never quite materialized. Or maybe it's something totally else -- but regardless, it's Taylor's truth to divulge or not, and unlike with most of her love stories over the years, the song doesn't seem to encourage you to find out on your own.

Of course, making this song all the more improbable are the names of the other writer-producers who worked on it: Louis Bell and Frank Dukes, two of the most bulletproof hitmakers in the pop universe right now. To get the guys responsible for "Sucker," "Havana," and countless other late-'10s smashes, and have them work on a song that couldn't have less of a chance of getting on top 40 radio if it had a spoken-word bridge from Andrew Dice Clay, is an unconventional strategy to say the least -- and one the trio don't follow on their other two Lover collabs, the much more conventionally accessible "I Forgot That You Existed" and "Afterglow." But to use such big names to craft such a unique entry in her catalog with "It's Nice to Have a Friend" -- and the production is one of their most spellbinding -- shows that the song is probably one she considers pretty special, even if its positioning on the album would suggest otherwise.

And really, showing up as the penultimate track -- after the two big singles, before the closer, basically the equivalent of the SNL 12:50 AM sketch -- might actually be the perfect spot for "It's Nice to Have a Friend." With the hits placed so far down the track order, buried as near-afterthoughts, it'd be natural to assume that the set was already well into wind-down mode by the time you get to this 2:30-long deep cut. Then "Friend" appears like an apparition, otherworldly and out-of-time, making you question everything you thought you knew about the album. It's the hidden treasures that really make record like Lover worth getting so excited for.