The Button.

A blood-spattered smiley face button.

A familiar symbol for comic book fans and even non-comics fans given that Time magazine named its source material as one of the major literary feats of the 20th century.

It is a symbol associated with “The Watchmen,” a ground-breaking graphic novel by Alan Moore and Dave Gibbons. Written in the 1980s, it imagines an alternative world where Richard Nixon has been president for nearly two decades and a disbanded group of superhero crime-fighters must piece together the mystery involving the murder of one of their own. A crime scene that leaves behind the blood-spattered smiley face button.

The button is on the cover of the million-plus selling “The Watchmen” graphic novel, was prominently displayed in promotional materials for the 2009 movie adaptation and is a central image in the HBO series scheduled to premiere in October.

And it is the central image and title of “Batman/The Flash: The Button,” a miniseries reprinted in collected format. While Batman and the Flash attempt to learn the secret behind the button, they become involved in an alternative timeline where Bruce Wayne is killed and his father survives — a world where the death of a young Bruce Wayne goads Thomas Wayne into becoming the Batman.

The skewed timeline also meshes the worlds of “The Watchmen” and the regular DC Universe, leading to the mini-series “The Doomsday Clock” which has been slowly ticking out one issue after another for the past couple of years.

But “The Button” sets the stage for the mini-series crossover event. And “The Button” is a fine bit of storytelling on its own.

Rarely are Batman and the Flash left to work together, just the two of them. Given their mutual dedication to criminal forensics — which this series emphasizes, it’s surprising they don’t work together as a duo more often.

The pairing is fun especially mixed with several wow moments such as Bruce and Thomas speaking to one another as son and father and about both being the Batman. And an iconic transition of the red on yellow blood-spattered button to the red on yellow of Superman’s chest plate.

Knowing the outcome of “The Button” does not lessen the impact of these and other moments written by Joshua Williamson and Tom King with art by Jason Fabok and Howard Porter.

“The Button” will put a smile on your face.