Dana ("Mack") MacKenzie lost almost 2 decades of her life to false imprisonment in Canamar. Framed for smuggling the drug Etrotherium, life passed her by as she lost her shortstop's job with the Titan Bluebirds. And she never got almost 20 years' worth of letters from her second cousin, Martin Madden.

Now she's got a chance. She's got a new Gorn ship, shaped like a cylinder, that's she's dubbed the Cookie. Her new engineer, Wesley Crusher, is back from time with the mysterious Traveler. Her communications officer is a third caste Daranaean artist named Crita. And her pilot is an Orion-Betazoid hybrid, Daniya.

She's hiring team members. They're going to barnstorm the galaxy, even though Mac is now fifty and not what she once was. But there's a bit of barely legal technology on the Cookie, and someone wants it – someone who's going to get on her team, by any means necessary. And there are others who want it, too, and are willing to kill for it. 

And what of Marty Madden? He's been supervising a project where he and Geordi LaForge have been detecting odd energy readings, something about a hydrogen line that doesn't match the one in our universe. Someone's knocking from another universe. Someone who maybe they shouldn't let in.

Mack and Marty hold a legacy in their genes, as do only a few other people. The descendants of Douglas Jay Hayes Beckett are going to have their hands full soon.