In all of her adventures, River Song has hung out with an impressive array of Doctors but perhaps none as iconic as the next Doctor on her checklist.
Big Finish have announced that along with her previous appearances with Matt Smith, David Tennant and Peter Capaldi in the Doctor Who TV series and Paul McGann, Sylvester McCoy, Colin Baker and, in a upcoming adventure, Peter Davison, Alex Kingston’s River Song will be joined by none other than the Fourth Doctor himself, as played by the indomitable Tom Baker.
Baker and Kingston will record the stories (which take place in a different point in River’s timestream than when she met the other Doctors) for the fourth series of ongoing collection The Diary of River Song, following adventures with the Eighth, Sixth and Seventh Doctors in series one and two.

There are no further details about Kingston and Baker’s adventures, as there’s still a whole other series of River Song’s diary entries to get through first before series four lands.
To tease us a little more, Big Finish have shared a few details about the Peter Davison starring series three which will also see the return of Madame Kovarian, played once again by Frances Barber.
The Lady in the Lake by Nev Fountain
On Terminus Prime, clients choose their own means of demise. Something exciting, meaningful, or heroic to end it all.
But when River discovers that there are repeat customers, she knows something more is going on.
She begins to uncover a cult with worrying abilities. Its members can apparently cheat death, and that’s not all they have in common with River…
A Requiem for the Doctor by Jac Rayner
River has joined the Doctor and his friend Brooke on their travels, and they stop off in 18th century Vienna.
Brooke thinks history is dull. Until people start dying.
Mozart’s legacy is not just his music. River has more than one mystery to solve before a killer is let loose on the people of Vienna – and on the Doctor.
My Dinner with Andrew by John Dorney
Welcome, Mesdames et Messieurs, to The Bumptious Gastropod.
The most exclusive, most discreet dining experience outside the universe. For the restaurant exists beyond spacetime itself, and the usual rules of causality do not apply. Anything could happen.
It is here that the Doctor has a date. With River Song. And with death.
The Furies by Matt Fitton
Stories of the Furies abound across the cosmos: vengeful spirits hounding guilty souls to death. Madame Kovarian taught them to a child raised in fear, trained to kill, and placed inside a spacesuit.
Kovarian knows the universe’s greatest threat. The Doctor must be eliminated. An assassin was created for that purpose.
But if Melody Pond has failed, Kovarian will simply have to try again…
The Diary of River Song Series Three will be released in January 2018.
You can pre-order each series of The Diary of River Song, from the Big Finish site at £23 on CD or £20 on download.