- Stony Blyden as Max Hunter
- MaeMae Renfrow as Tess Hunter
- Daan Creyghton as Sal Hunter
- Thomas Jansen as Daniel Hunter
- Kyra Smith as Anika Hunter
- Yootha Wong-Loi-Sing as Simone
- Ronald Top as Erik Hunter
- Tooske Ragas as Kate Hunter
- Zoë Harding as Sophie Saganash (uncredited)
- Cees Geel as Mr. Bruhl
- Liora Kats as Janine Bruhl
- Amedeo Feingold as Julius Bruhl
- Dawn Mastin as Gertrude
- This episode shows Mr. Bruhl's house as Anika goes through it to find out exactly what he wants with the Hunter house. As well as showing his connection with Saganash. It also features an appearance from the Hunter kids' parents, Kate and Erik . They travel to Indonesia to the Java Sea to retrieve the red diamond, which they do. In this episode, Saganash attacks Gertrude, one of the Relatives, a group of people who want to protect the Hunter fortune, and he steals the blue diamond off her after the Hunters gave Saganash a fake one made by the Magpie instead of the real blue diamond. It features the first appearance of Sophie, Saganash's daughter, who is trapped after she is caught trying to steal something from the Hunter house after she broke in using the tunnels.
- All the Hunters find out about the connections of Mr. Bruhl to Saganash in this episode.
- This episode marks the first appearance of Sophie.
- Anika pictured an architectural blueprint that shows an image where Bruhl wants to buy the Hunters' house.
| To view the Undercover gallery, click here.
|Hunter Street Episodes|
|The New Hunter • Saganash • The Secret Room • Principal • Rinus • The Key • The Blue Diamond • MGP • Aunt Hedwig & Uncle Eugene • Contact • The Relatives • The Red Diamond • Cassandra's Map • Anika's Birthday • The Maze • Undercover • Sophie • Bruhl • Almost Back • The Deed|
|The Package • The Arrest • Max • Evie • The Museum • The New Friend • The Family Tree • Payback • The Plan • The Reverse Heist • The Mole • The Green Mask • Hacker Hideout • The Super Secret Room • The Crown • Hide and Seek • The Houseboat • Spy • The Ritual • Hunters Forever|