The last time we saw the puppy called Cole — which was also the first time we saw him — was at the end of December.

He was seven weeks old, he wore a purple collar and he peed on our living room floor. We were wholly charmed.

But we were also charmed by his twin brother, Calvin, also seven weeks old, wearing a blue collar. And we could only keep one of them.

The puppies were visiting from Heart of a Border Collie rescue. We played with both, but Calvin responded a little better to our six-year-old Lab, Rosie. Cole barked at her, and his foster parents said he was a little more assertive than his brother. That (plus Calvin’s white-tipped tail) helped me decide. Rosie has a huge personality. She needed a mellow brother. (Plus one with a white-tipped tail.)

We said goodbye to Cole, we kept Calvin, we changed his name to Angus, and the rest is history. But we always wondered what happened to that other little black puppy.

A few weeks ago, we found out.

I got a note from the woman who adopted him, and it turned out they lived just a few miles from us.

Cole’s name now is Winston, she wrote, and he is “a good mix of fun.”

“In the puppy classes to which I’ve taken him, he seems to be the party starter — playing, wrestling, as much as possible,” she wrote. “That day when the rescue brought him to our place and he walked right over to his bed and lay down next to me, I knew he was our new pal.”

We made a date for an Angus and Winston reunion, but, I must admit, I was a little worried as we walked up to their back gate. Angus is not always happy to meet new dogs. He has tons of dog friends, and he plays with them jubilantly, but there are also dogs that he hates on sight for mysterious reasons.

For instance, Stella, the sedate black Lab who lives down the street — he hates her. Who knows why. And Duke, the supremely well-behaved golden retriever: Angus hates him, too. (Duke and his owner are both completely unflappable. If Angus goes all Cujo on them, they just quietly walk on.)

What if he hates Winston? Murder is one thing, but fratricide?

We opened the back gate and braced ourselves.

Winston sat by his owner about 10 feet away from us. Angus saw him and started to growl. Then he started to bark. Winston barked back.

“Oh, dear God, preserve us,” I said, and with trembling fingers I undid Angus’ harness. The dogs sprang free — and right at each other.

And they began to play.

They raced around the yard, first Angus in the lead, then Winston. They rolled each other. They bared their fangs and flashed their teeth and raced around some more.

They ran up the porch stairs to the water dishes and they each drank from a dish, and then they switched dishes and drank again. And then back down the stairs and around the yard.

Winston is a little bigger than Angus — stockier, with broader shoulders and a wider face. His ears stand straight up, while Angus’ collapse to the left. Winston seems (oh, irony) a little mellower than Angus.

They played and played and after an hour they were spent and panting and soaking wet.

Had they remembered each other? Who can say?

But they’ll remember each other the next time, that’s for sure. It’s good to have friends. It’s even better to have a brother.

Laurie Hertzel is the senior editor for books at the Star Tribune. She is not a dog expert, just a dog lover. She is chronicling the first year in her puppy’s life here.

Coming Aug. 11: Gate is open! Dogs are gone! Follow along at startribune.com/puppy