This novel takes place immediately after the first episode of Season Two, with the Psychon Maya being taken back to Moonbase Alpha and how she tries to live amongst humans. There's some tension between her and Tony Verdeschi at first, as he's still (and understandably) upset that her father, Mentor, had tried to kill them all. She tries to adapt to living with these humans and is given Victor Bergman's quarters to live in, since he's been presumed dead (all explained in the previous Powys books). It's here that she comes across his diary, which gives some very interesting backstory to the doctor. The Alphans come across the planet Ekimmu, which the Psychons had visited years before. It's a strange ocean world with red colored seas-and it's supposed to be haunted. The only one who had returned from it was Maya's father-and he was insane. They do figure out that there is an energy on the planet-and end up helping the remnants of this ancient civilization so that they can escape back to Moonbase.
THE WHISPERING SEA is one of the better Space 1999 Powys books. It really captures the Maya character and does an excellent job of bridging the two seasons of the television show. Highly recommended, you won't be disappointed.