This could well be "The Mick of Time" by Spider Robinson. It was first published in Analog, May 1986 and subsequently anthologized in Callahan's Secret.
It's not a perfect fit, it's about a decade later than your guess, but the crowd at Callahan's form a group mind to meet and fight off Mickey Finn's alien master who has come to Earth to reclaim him.
The risk was horrible. A Master is not defended as well as a scout either.
It was a mad gamble, and The Beast knew it, but it was a pervert and doomed. Desperate and raging, it had followed the trail of Txffu Mpwfs across the big empty spaces to the place where he was known as Mickey Finn, hoping to find some terror weapon it could use to avenge itself, and found a bunch of barflies, a few time traveling Micks, two telepathic psychiatrists and a talking dog. Callahan's Bar on New Year's Eve.
They do bluff it with a time limit:
This time period (*) is a second, we bellowed calmly. You have thirty of them in which to bargain for your life.
But the Beast thinks much faster than they do, and has out-planned and overpowered them:
In the instant of opening communication we had told The Beast the rate at which we processed information-by establishing a second as a significant interval for us-and it had been outthinking us ever since. It had had plenty of time to spot Paul stumbling around in the back of its brain, without alerting him. It had learned a great deal about telepathy from him, and then had hidden in his pocket, as it were, and been brought back home by him. His databroadcast had opened us all up, allowed The Beast to access our files and study us. Our cover was blown sky-high. Jim and Paul MacDonald were effectively dead, their minds torn out, their personalities annihilated, their bodies and brains kept alive to serve The Beast as a telepathic transceiver.
I was caught. Swallowed by The Beast. Damn it, it was just like being swallowed by a Beast, the size of the one that got Pinocchio. My surroundings went away, my telepathic companions went away, my eyes and my mind found black nothingness in all directions-I tried to cast around with my arms and discovered that I could not find my body anymore. The audible screams, including my own, were now inaudible; so were the mental ones. There was just the Master and me. All my strings were cut.
It's not a cliffhanger ending though, Mike Callahan time travels out of the Beast's reach, frees the others and they nuke it.
And of course this is part of Robinson's Callahan series.