After "Sherlock" returned in a blaze of glory in last week's "The Empty Hearse," this week's episode, "The Sign of Three," was all about the Watsons. As John Hamish Watson and Mary Elizabeth Morstan tied the knot with the help of one high-functioning sociopath, their nuptials were interrupted by (what else?) a murder plot in the making, then interrupted again when Sherlock dropped a deduction bomb on the couple's first dance.

Don't Send In The Clowns
If you've been wondering whether Lestrade solved any crimes at all in Sherlock's absence, the episode's opening montage is for you. In it, Lestrade is revealed to have spent the past two years in pursuit of the Waters family, a gang of masked bank robbers who, despite being repeatedly caught and prosecuted by Scotland Yard, have managed to walk free every. Single. Time. But this time — in a moment eerily reminiscent of the opening scene in "The Dark Knight" — the thieving clowns are about to get caught in the act, and it'll be vindication for Lestrade at last. Except that just as the bust is about to go down, the inspector gets a desperate text that sends him bolting for Baker Street. What horrific crisis could tear him away from the case of his career?

May The Best Man Win
Though Sherlock has been ever so helpful to the wedding planning process thanks to his unique skill set — which includes but is not limited to reading between the lines on the RSVPs, discerning which of Mary's male friends have designs on her, and folding napkins to resemble the Sydney Opera House — there's one responsibility that has him stumped. As Lestrade charges into the flat, guns blazing, closely followed by every police car in London, Sherlock looks up with despair from a book titled "How to Write an Unforgettable Best Man Speech" and says, "Do you have any funny stories about John?"

Staggering Genius

Sherlock has planned Watson's stag night down to the milliliter, as the pair take a bar crawl down memory lane in a state of perfectly calibrated drunkenness. But when Watson surreptitiously spikes their drinks with additional booze, the two end up back at Baker Street, wasted, with a client who swears that she dated a ghost. With the enthusiasm that only two drunk dudes could muster, Holmes and Watson stumble their way to a dead man's apartment and proceed to start "clueing for looks." Alas, Sherlock's ability to deduce while drunk is, um, compromised.

There Are No Words To Describe This Speech This episode contained plenty of more subtle hints at Sherlock's deep affection for John, and particularly his anxiety at the possibility that John's marriage might spell the end of their detecting adventures. But even if you missed those, you couldn't miss the flashback to Sherlock being struck dumb at John's asking him to be his best man (also known as further proof of the sheer power of Benedict Cumberbatch's face.) And you definitely couldn't miss this:

John, you have endured war, and injury, and tragic loss — so sorry again about that last one — so know this, today you sit between the woman you have made your wife and the man you have saved. In short, the two people who love you most all this world.

Let's be clear: that was not us who dialed 911 during this scene because our heart was exploding repeatedly with the sheer force of all those feelings. You did that. Honestly, you should learn to contain yourself.

The Best Man Vs. The Mayfly Man
It wouldn't be an episode of Sherlock without a case to solve, so how convenient that one presented itself right in the middle of the Watson nuptials. The suspect: the Mayfly Man, an elusive serial dater who'd been wooing London's ladies under the assumed identities of recently deceased dudes. Deducing that Mayfly's target is Watson's reclusive former commander, Sherlock leaps into action with John and Mary close behind. Clearly, Miss Morstan won't be putting a damper on the duo's crime-solving shenanigans... although she may insist on being invited along from time to time.

A First Dance, A Last Vow, And A Surprise Guest
Oh, and just one more deduction to finish the day. Mary? You're pregnant. BOO YA.