It's been years since Mare Do Well was last seen. Equestria has changed since then, and what should have been quiet retirement ends when a new threat comes to life in the city of Seasaddle. Is Mare Do Well up to the task, or is she outdated?
As the years go by, dear sweet Canterlot decays as mysterious disappearances and extrodinary claims of violent crimes are on the rise. Only a myserious shadow in the night has the means to stop it. But, who is she and is she connected to any of this?
The Dark Pony of the Night, Mare Do Well is out hunting the musical villain Music Mull who wants to control the whole world with his mind control singing and this number is abut how he feels about Mare Do Well making him and everypony else unwell.
Decades after the sunshine and rainbows day, Equestria slowly began to bring back it's old traditions. Now, on Nightmare Night, three fillies found themselves in danger, but luckily for them, a mysterious vigilante appears to help them.
Daring Do and Mare-Do-Well join forces to take on the criminal organization, H.U.R.R.I.C.A.N.E. who have planned to unleash widespread chaos upon Equestria. Can Daring Do and the Mysterious Mare-Do-Well stop them in time?
Rainbow Dash a.k.a. the Dash, is long gone. Mare Do Well tries to keep the crime in Manehatten down but it seems that Rainbow is still alive and trying to tell Mare Do Well and the other Dashes that this is so.
Trixie concocts a plan to revive her tarnished image; take up the mantle of Mare-Do-Well and claim the credit for herself. When Shining Armor begins to pursue the aspiring vigilante, Trixie struggles to decide if the life of a hero is really for her.
After the mysterious murder of her parents, Twilight Sparkle must don the cape and cowl in an effort to discover the killer. Meanwhile, Discord has set about procuring her a mentor in crime-fighting.
Sunset Shimmer's Hearth's Warming Eve celebration is cut short when she spots a suspicious figure lurking outside. After a festive costume makeover, she sets out as the Mysterious Mare-Do-Well to investigate.