Batgirl, Robin and Man-Bat take part in a full length story in Batman Family 13 (Aug/Sept 77), the only issue of the book that would contain a full lengther. The art is by Don Newton, Marshall Rogers and Bob Wiacek. Aparo does the cover.
Picking up from the end of the previous issue, Batgirl and Robin each arrive in New York city, strapped to their motorcycles and out of control. Although nothing bad happened along the way, once they are in New York the bikes do all they can to kill their passengers, ultimately colliding in a fiery crash. Batgirl and Robin manage to undo each others bonds and get free just in time.
For Robin, this somehow counts as an excuse to make out. Batgirl is more serious, pushing the boy away, and pointing out that she kept seeing Alfred while they were zooming around. Did you notice him at the window in the page I reproduced above?
The story then jumps to follow Kirk Langstrom. He and Francine are watching a new report, broadcast by Martha Roberts, from the Freedom Fighters book, about the events in the park in the previous issue, and Batgirl and Robin's mad bike ride. Kirk becomes Man-Bat to go hunt for the Sunset Gang, who had got away. There is a knock at the door, which Francine answers, and which teases the next plot thread for this series.
Man-Bat finds the Sunset Gang, and this time manages to take them down. But they are not the real threat. This time he gets to meet the mysterious Mr. O, the Outsider. Batman's old foe from the 60s, an alternate persona for Alfred, somehow grabs the Moon (must be an effect) and uses it to split the were-jaguar that Man-Bat had become out of his body.
So Man-Bat now has to battle his former were-jaguar self, while the Outsider takes off to kill the rest of the Batman family.
Robin brings Batgirl to Gabriel's Horn, the nightclub that serves as a base for the Teen Titans. They hook into the JLA satellites to hunt for the Outsider, and Robin decides to profess his love for Batgirl. She sleeps through it. Or at least pretends to. The Outsider then takes over their computer, and then their belts, binding and capturing the heroes.
The Outsider summons the were-jaguar, and tells the heroes how it killed Man-Bat. He leaves the were-jaguar to kill Batgirl and Robin, and heads off to go kill Batman.
But of course no one has died. Well, except the were-jaguar. Man-Bat killed it with a silver trident that happened to be conveniently lying around, skinned it, and then wore its pelt when it came to the Outsider. Yuck. So instead of killing Batgirl and Robin it just freed them. Why they didn't attack the Outsider at that point is unclear. Maybe Robin needed to make another profession of love. At any rate, they catch up with the Outsider for a big bridge battle. Oh, I forgot to mention that it was being tackled by Commissioner Gordon a number of issues back that gave Alfred the head bump that revived his Outsider self.
Man-Bat uses the special flashlight, the Moon-Beam, that had made him a were-jaguar on the Outsider, which has the effect of splitting Alfred out of his body. Without Alfred as part of him, the Outsider loses his supernatural powers, and its the battling butler who actually defeats his evil side.
The story ends with a tease for the next issue, as Batwoman comes to see Barbara Gordon, but melts away into a blob of goo.
The issue also contains another page of really horrible costumes for Robin. The best one makes him look like a pirate. Enjoyably, this one was drawn by Batman artist-to-be Norm Breyfogle!