The family follows the fortunes of three very different birds: kingfishers, dippers and moorhens, to see if they can survive what is the most dangerous season of their year.
After having their first nest raided, the kingfishers have now mated again. There is a problem though, and it's something that Charlie has never witnessed in over two decades of studying these small bright birds: the male has run off with another female.
With cameras wired to a moorhen's nest, the family watch the chicks hatch in a tree, and then look on as a tragedy unfolds. And Charlie creates the world's first underwater bird table in order to see how dippers hunt for submerged prey.
Philippa, meanwhile, makes a plan to protect the vulnerable water vole population on the river and charges Charlie with the job of filming them. His mind is elsewhere though; Charlie's busy building the ultimate otter des-res. Equipped with cameras, he wants get an insight into the private life of these elusive creatures.
Spring is a beautiful time on the river, the mayflies have just 24 hours to spin, dance and mate in the sunshine after two years as larvae in the mud, but despite its beauty, the family's film diary reveals that life and death for the creatures on the river are never far apart.