The massively popular "Fast & Furious" series has amassed more than $1.5 billion dollars to date, building its business on keeping the franchise going … and going and going.

Lately that means adding enticing teasers after the credits start rolling, designed to keep "Fast" fans coming back for more.

The post-credits scene in "Fast & Furious 5" blew everyone's mind when U.S. customs agent Monica Fuentes (Eva Mendes) hands Hobbs (Dwayne "The Rock" Johnson) a very interesting file. The big reveal: Letty (Michelle Rodriguez) is alive! (She was thought to have been murdered by way of a fiery car crash in the fourth installment, "Fast & Furious.")

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While Mendes doesn't appear in "Fast 6" – in which a very alive-yet-confused Letty emerges – another revealing post-credits scene does.

For "Fast" fans, the post-credits scene in "6" is eye opening on two levels: 1) The series's precarious timeline is deftly ironed out. 2) The new villain – and it's a big one – makes a major debut-slash-cameo.

If you follow the series you know that the third installment, "Tokyo Drift" (which came out in 2006), takes place after "Fast" 4, 5, and 6. Why do we know this? For one, Han (Sung Kang), who died in the third "Fast," is alive in those latter three installments.

[Related: 'Fast & Furious 6' Girl Fight: Most Intense Ever?]

SPOILER ALERT!

After the credits role in "Fast 6," we see Han die all over again. Same race in Japan, same car flip. And now we can finally map out the chronology of the series, which is: "Fast" 1, "Fast" 2, then skip to "Fast" 4, "Fast" 5, "Fast" 6, then back to "Fast" 3 (that pesky "Tokyo Drift"), then forward with "Fast" 7 (coming out next year).

And did we ever find out who actually killed Han? No. But we do get to find out in the "Fast 6" post-credits scene!

Han dies after a mysterious black Mercedes sideswipes his car, causing it to flip. And guess who gets out of the dark stealthy car to check Han's lifeless corpse …

SUPER MASSIVE SPOILER ALERT!!!

… Ian Shaw, played by none other than British action star Jason Statham (the brother of the "Fast 6" super-villain known simply as Shaw, played Luke Evans). Evans's character dies at the hands of the "Fast" crew in the sixth installment, out now. Statham's man is clearly avenging his brother's death.

The series has come full circle. And Han's death is finally explained.

Of course, if you check the IMDb page for "Fast & Furious 7," you'll see Statham's name at the top of the credits listing under the character name "Ian Shaw" and that the film is in pre-production. But for fans of the series, this is a huge development.

Now we get to ponder a "Fast" installment with yet another huge personality to bring to the mix: The Rock, Vin Diesel, Michelle Rodriguez, and the addition of Mr. Statham.

Director James Wan, known best for his long running "Saw" horror franchise, has taken over the series from Justin Lin. And he has his work cut out for him when it comes to balancing those big players, ahem, drivers.

Watch 'Fast & Furious 6' Cast Discuss Film's Ultimate Girl Fight:

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