The couple only planned to adopt one new kitten — but when a second kitten wriggled into their lives in an unexpected way, their plans suddenly changed.

In September, the couple had contacted , a rescue group in Idaho, to express . They already had another cat, so they wanted to add one more feline to their household.

Emily Sullivan, treasurer for the group, invited them to her home, where she was fostering three kittens, Artemis, Hercules and Apollo. The kittens were all , and they’d been rescued from a farm after their mom was hit by a car.

"We went into my living room, and all three kittens were just running around, playing and being cute,” Sullivan told The Dodo. “People like to make a connection with the animal that they’re going to support for the rest of their lives … and they loved Artemis. She was crawling up in their laps.”

It didn’t take long for the couple to decide to adopt Artemis — so Sullivan went upstairs to get a cat carrier for them to borrow.

“I put one of their blankets in it, and I put it down on the living room floor, and I was just wandering around to look for Artemis so I could put her in,” Sullivan said.

“It was about 10 o’clock at this time, so it was late. My living room had mood lighting, so it wasn’t very bright in there.”

When Sullivan found Artemis, she kissed her, put her inside the carrier and closed the door.

“When they went to leave, one of them held up the carrier so I could look inside,” Sullivan said. “I looked in and I saw Artemis’ face, and I said, ‘Bye, baby. Be a good girl. Live for a long time.’ Then I saw them out the door.”

Not long after that, Sullivan received a text message from the couple as they drove home.

“They said, ‘Oh my gosh, she’s been and she’s so happy. She’s just the sweetest little girl,’” Sullivan said.

But when the couple got back to their own home and opened the carrier door, they discovered the reason Artemis had been purring so much. Her brother, Hercules, had hitched a ride in the carrier with her. Since he had black fur, no one had seen him hiding in the back.

“They called me and said, ‘You’re never going to believe this,’” Sullivan said.

“And I said, ‘What?’ I was worried something happened.”

They explained what Hercules had done, and Sullivan was full of apologies.

“I was like, ‘Oh my gosh, I’m so sorry. Can we meet tomorrow before work? I’ll get the carrier from you. I’ll meet you halfway, and take the kitten back home,’” Sullivan said.

The couple agreed to care for Hercules overnight, and meet Sullivan the next day. But the next day, they changed their mind, and they called Sullivan back.

“They just said that they loved him [Hercules], that he’s so sweet .

.. and they wanted to adopt him as well, if that was OK,” Sullivan said. “And I was like, ‘Yeah, you betcha.’”

This certainly wasn’t the couple’s initial plan, but they’re pleased with how it all worked out.

“They just love the two kittens, and the two kittens love each other, and they’re all getting along with the resident cat that they had before,” Sullivan said. “It was something they didn’t expect, but they’re very happy about it.”

Twelve days after Hercules and Artemis were adopted, Apollo found his forever home, too — and Sullivan is thrilled by how everything worked out for all three kittens.

You can help rescue more kittens like Hercules, Artemis and Apollo by .