Set in Manhattan, The Secret Formula follows the adventures of Bella, a cool, skateboarding champion and daughter of a glamorous fashion editor, and her friend Felix, a jazz musician and crime buff. Felix is convinced New York is still a seething mass of hard talking criminals - Bella laughs at him but Felix will have the last laugh. Doc Gutson and her band of misfits scheme to steal the Secret Formula for a new perfume which will make the wearer irresistible. But, while securing the Secret Formula will bring Doc Gutson riches beyond her wildest dreams, her other motive for moving into Bella's apartment becomes apparent as revenge drives her to destroy Bella's life. Can Bella and Felix thwart Doc Gutson and her evil henchmen Johnny Sequins and Pauly Three Toes? Or will they end up in the East River wearing cement shoes? Noir for tweens.

Things aren't going too well for Doc Gutson—incarcerated ('sent up the river' as Felix would say) in St Agatha's Prison for Wayward Women in upstate New York, the Doc has had her work cut out for her making her Gang the biggest and meanest in the tri-state area. One thing keeps her going—her hatred of the Street family and her burning thirst for REVENGE. Blissfully unaware of the Doc's plans for escape and retribution, Bella is enjoying a vacation in England with her mom, Emerald, and Professor Mortimer, who is working on another great invention. Things soon start to go wrong with Bella's plans, however, and before long she is fighting for her life. Can Bella and Felix track down the mysterious 'Excalibur' and outwit the Doc for a second time? It seems as likely as finding a snowball in the Sahara... The Doc wants revenge and it's not gonna be pretty...

In The Fat Lady Sings, Bella Street and her tech-wizard friend Felix Samson have been hidden in the Witness Protection Program to keep them out of Doc Gutson's evil clutches. Unfortunately, the Doc has hired the worst of the worst, Marky Blue-Eyes and Carlos the Moose, to track them down. Will Bella and Felix manage to stay one step ahead of the Doc and her henchmen? Will Bella and Felix ever find out what Excalibur is? What will Johnny Sequins and Pauly Three-Toes do if the Doc finally goes off the deep end? All good questions. One thing's certain, it won't be over 'til the fat lady sings... The third instalment of the Tween Noir Bella Street Mysteries series.