28 September 2006
At the local boat yard, Emma finally meets the mysterious old woman who has been following Cleo around; Miss Chatham. And she finds her at just the right time, as Miss Chatham has an argument with Zane about an accident involving her houseboat ("Lorelei") and his jet ski, and then collapses from a heart attack. As she is taken away in an ambulance, Zane hears her muttering to Emma that she needs to protect her ‘treasure'. Later, Emma invites the fragile Miss Chatham to stay with her, and she, Cleo and Rikki get to know her better. But upon hearing that she has been evicted from the boat yard, Miss Chatham sets off in the Lorelei before it can be taken away from her but she accidentally damages Zane's Jet Ski. Zane chases after her in his Zodiac pontoon boat, catches up with the Lorelei near Mako Island, and boards the Lorelei. He demands compensation for his damaged jet ski, but Miss Chatham passes out with another heart attack. Emma and Lewis arrive just in time to help Miss Chatham and take her to seek medical care on Lewis' boat. Zane stays aboard the Lorelei, searching for the treasure. Kerosene from a lamp ignites on the Lorelei's engine, and the boat begins to sink, trapping Zane. Emma is forced to dive down to the sinking boat in order to save Zane, and risks him discovering that she is a mermaid, but he just glimpses her tail before he passes out. Emma returns Miss Chatham's "treasure" to her, and it turns out to be a locket (identical to Cleo's locket), containing a picture of three teenage girls; herself and her friends Julia and Gracie, who were all mermaids back in the 1950s (Cleo's locket belonged to Miss Chatham's friend Gracie).
- Emma appears to drink from the glass that Mrs. Chatham gave her, but she doesn't actually drink anything.
- The Sea Monster storyline is continued on for the rest of the series.
- The scratch on Zane's jet ski that he says was from Mrs. Chatham's boat is facing the port.
- The picture of the girls were wearing the same outfits they wore in Dangerous Waters.
- It was possibly after the events.
- The original mermaids are seen for the first time in a photo.
- International Airdates:
- Denmark: March 8, 2008 on Jetix
- Poland: September 23, 2007 on Jetix
- This episode aired in the United States on May 25, 2008 on Nickelodeon.
- Last episode directed by Colin Budds.
- Lewis: (about Miss Chatham) Some people say she's a witch.
- Rikki: And if they said she was an Easter Bunny would you believe that?
- Lewis: There was a time I didn't believe in mermaids either.
- Miss Chatham: They're just after my treasure!
- Zane: You are a disgrace to this port! You left a scratch on my boat!
- Emma: I bet you will.
- Rikki Chadwick - Cariba Heine
- Emma Gilbert - Claire Holt
- Cleo Sertori - Phoebe Tonkin
- Lewis McCartney - Angus McLaren
- Zane Bennett - Burgess Abernethy
- Nate - Jamie Timony
- Elliot Gilbert - Trent Sullivan
- Neil Gilbert - Jared Robinsen
- Lisa Gilbert - Caroline Kennison
- Wilfred - Ariu Lang Sio
- Louise Chatham - Christine Amor
- Hendrix - Steven Tandy