Abbey Grey is Zak's babysitter in the comic Way Past Bedtime. She brings him, along with Fiskerton and Komodo, to The Tomb of Antiochus of Commagene to search for Antiochus' Ivory Scepter. Although she is not one of the remaining Secret Scientists, it's worth noting that the Saturdays trust her enough to babysit Zak.
She then appears in The Kur Guardian to help Doyle, Zak Saturday, and Fiskerton discover Fiskerton's Lemurian heritage. After they figure out Fiskerton has to protect the world from Kur, Doyle asks her out on a date, which she agrees to. In the next episode, Food of the Giants, she betrays the family and reveals that she has been Van Rook's new apprentice since Doyle quit. She flees at the end and tells Zak and Doyle to tell their family that she is sorry but she has to because of the money, which proves she's perfect for Doyle. Her next mention was In Kur:Part One, Leonidas Van Rookmentions to Doyle that she took over his business.
She appeared in The Return of Tsul 'Kalu, where she demonstrates a much better knowledge of the field of mercenary work than Van Rook, as she is not only able to make more money, but also is able to buy higher grade equipment due to her not being as much of a cheap skate as her former teacher. It's also shown that she, like her teacher, has come under the employment of V.V. Argost. In the end, she's defeated by Doyle and he sees her walking away and decides to let her go.
- Abbey Grey is the younger sister of Dr. Miranda Grey so she may or may not have been a secret scientist, but no longer since she became a villain.
- When betraying the Saturdays she said to Doyle, "But my feelings for you . . ." meaning she might of actually did (and maybe still does) like him.
- It is unknown if she knows that Zak is Kur, or if she'll ever go after him again.
- Abbey does not appear at Van Rook's funeral.
- She once gave a nickname to Fiskerton Lovely-Locks.
- Abbey's_Hovercraft.jpg. She played a video game with Doyle.
- It could be possible that since she is under the employment of Argost she could now be a threat to the people closest to her (the Saturdays) and Miranda Grey, her older sister.
- Her appearance in The Return of Tsul 'Kalu is different than her appearance in Food of the Giants. Her weapons are better and her wrist blaster has a bullet holder that wraps around her wrist.
- Abbey is shown to still care about Doyle since she said, "Once I'm done with you there'll be nothing left of you to miss!"
- It is unknown if she and Miranda are going to come face to face in battle in the series.
- Her role seems to be the opposite of Doyle's. He was an apprentice to Van Rook who became an ally, while Abbey was an ally who became Van Rook's apprentice.
- "My feelings for you . . ." - Abbey Grey in Food of the Giants.
- "It's nothing personal . . . It's money." - Abbey Grey after revealing she was Van Rook's apprentice in Food of the Giants.
- "It's panda, you prat" - Her opening sentence in The Return of Tsul 'Kalu.
- "Once I'm done with you, there'll be nothing left of you to miss!" -Abbey to Doyle in The Return Of Tsul 'Kalu.
- Zak Saturday (possible arch-enemy and former friend)
- Doyle Blackwell (ex-boyfriend)
- The Saturdays (former friends)
- Van Rook (former boss; deceased)