It's time to say goodbye to Sherlock Holmes and Joan Watson.

Elementary wraps up its seven-season run on Thursday with its final episode ever, appropriately titled "Their Last Bow," which picks up three years after the events of last week's dramatic hour and reunites Sherlock (Jonny Lee Miller) with his trusty partner, Joan (Lucy Liu), one last time. 

It quickly becomes apparent how much things have changed in the three years since Sherlock faked his own death, a drastic decision made out of desperation to bring his nemesis, tech billionaire Odin Reichenbach (guest star James Frain), to justice. And when Sherlock makes a surprise visit in the brownstone he once called home, following Joan's secret call for help amid worries that his ex-lover Jamie Moriarty may be causing trouble, the ex-partners have a lot of catching up to do.

In ET's exclusive sneak peek, Sherlock rattles off just what he's been up to since he, you know, undid his own death -- and unsurprisingly, he's been keeping busy with the P.I. thing since losing touch with Joan. 

"I kept quite busy after my death. Traveled, first to Florence, then to Tibet, spent a good deal of time in Norway. You might have read about the wonderful exploits of a Norwegian named Sigerson," Sherlock proudly reveals to an not-so-amused Joan. "I suppose it never occurred to you, you were receiving news of your friend."

As he explains, assuming various identities all over the world has been "a boon" for the sleuth, as he spent the better part of his three years away targeting powerful criminals doing terrible things "from the shadows." But now that he's back from the dead, will he be able to keep Moriarty from striking again? Watch ET's exclusive clip above.

Earlier this year, Elementary boss Rob Dohertyoffered a glimpse into what awaits fans in the series finale.

"I'm very proud of the way we ended things. You hate to have one good finale and one bad finale. Even though I was nervous going into it and had a few sleepless nights as we started to search for another series finale, I feel really good about where we went," Doherty said in May. "I hope anyone who enjoyed the original series finale will enjoy this one just as much."

The Elementary series finale airs Thursday, Aug. 15 at 10 p.m. ET/PT on CBS.

To stay up to date on breaking TV news, sign up for ET's daily newsletter.

RELATED CONTENT:

'Elementary' Boss on the Surprise 'Blessing' of Season 7 and Wrapping Up Sherlock & Joan's Story (Exclusive)

'Elementary': Sherlock and Watson Have a Tense Confrontation in Season 6 Finale (Exclusive)

Lucy Liu Shares Her Behind-the-Scenes Photo Diary While Directing 'Elementary' (Exclusive)