About a year after John Graham and his wife, Kathleen Birch, adopted Bella the Cat, they noticed she had an acquaintance — a genial neighborhood stray with a white-cream coat and black fur running from his back to his tail like a cloak.

Although she’s territorial like any member of her species and spends much of her time patrolling Grove Park — a quiet London neighborhood tucked into a winding loop of the Thames — Bella expressed no animosity toward the apparent intruder, and in fact seemed to be on quite friendly terms with him.

Graham and Birch, who like to joke that Bella is a clandestine agent of MI5 — Britain’s version of the FBI — dubbed the stray Bertie, and decided he was her field liaison.

“We think Bertie is her Mi5 contact and visits to get updates [before] returning to HQ to report on her field actions and mission status,” Graham quips.

After checking with the neighbors and bringing Bertie to the veterinarian, who said the stray was not chipped, Graham and Birch believe Bertie was likely abandoned by his previous family and eked out a living zig-zagging between homes in Grove Park, depending on the goodwill of neighbors and his own considerable charm for food. So they had Bertie chipped with their contact details about eight months ago, and now field agent and handler have been united under one safe house roof as they continue in His Majesty’s service.

Bertie and Bella even have their own WhatsApp group comprised of their humans and neighbors, who post to let each other know of the feline duo’s comings and goings.

Both cats are a source of great joy for Graham and Birch, who were looking to adopt again two years ago after the passing of their beloved Bets, who had been with them since kittenhood and lived to the ripe old age of 21.

After contacting a charity they support in Twickenham, the couple went out to meet a cat named Puss Puss at a foster’s home about three miles away.

“We walked in and sat down, and within literally a few seconds, she came out from under a table. My wife immediately fell in love with her as Puss Puss – now called Bella — rolled over and showed her belly with the loudest purrs ever,” Graham recalled. “She walked over to me and looked up with the most beautiful green eyes, allowing pets and scritches instantly. I was totally smitten. Her secret service training on overcoming any resistance was obvious here.”

Not much is known about Bella’s past, which Graham jokes is classified, but the fosters said Bella likely came from a hoarding situation. She bears some emotional scars from those times, making it clear she didn’t like to be picked up and wouldn’t tolerate head rubs. Graham said he thinks Bella may have been struck on the head by the abusive person or people who had custody of her originally, but with patience “she has grown to trust us and love us the way we love her.”

True to her training, Bella came striding out of her carrier that first day without need for coaxing and set about surveying her new headquarters, exploring while noting promising hideouts and lounging spots.

“She immediately checked out the perimeter as do all good Mi5 agents, looked around and began a sniffing and snooping journey for about an hour,” Graham said, “Then sitting in front of us on a low stool, she started shouting loudly, her default way of demanding food. This prompted me into action, offering her different dishes attempting to find her favourite. It turns out that she basically will eat anything.”

Indeed, Bella’s love of food is one of the few things that cause a bit of tension between her and her doting humans. She’s restricted to carefully measured wet food plus veterinarian-suggested “weight management crunchies” and, like many cats, is not shy about notifying her servants when the yums are low or the auto-feeder isn’t dispensing them. (In those instances, Bella hops up onto the bed and approaches the sleeping Graham: “I will get the gentle paw followed by the sharp claw to ensure I get the message to come and feed her immediately.”)

Adopting a cat is always a guessing game. Will the cat relax and open up once she realizes she’s safe and has a home? Was he reserved when we met him because he’s been living in a shelter with unfamiliar sights and smells? Will she take to her new home immediately, or will she dive under a couch and remain there for weeks, emerging only to grab a bite from her bowl when no one’s around?

Those questions were immediately settled for Graham and Birch, and Bella’s outgoing personality is one of the things they love most about her, along with her supreme confidence.

“She has it in absolute truckloads,” Graham notes, “and there is pretty much no fear on her part about adventuring anywhere in or out of the house.”

While keeping cats indoors is the norm in the US, as many as nine in 10 caretakers in the UK allow their felines to spend time outdoors unsupervised, encouraging them to establish their territories, explore their gardens (backyards to us Americans) and familiarize themselves with their neighborhoods.

Many US shelters and rescues won’t allow potential adopters to take a cat home if they indicate they’re willing to let the kitty outside, and some even require adopters to sign contracts stating they’ll keep their four-legged friends indoors. UK cat rescues often take the opposite stance. They advise pet parents on how to gradually introduce their cats to the outdoors, offer tips on how to manage their outside time and recommend various pet flap configurations.

The difference is partly cultural and partly practical. While extolling the benefits of allowing cats to roam, UK cat lovers point out that domestic felines rarely stray far from their homes, on average venturing only between 40 and 200 meters (about 130 to 650 feet). They’re curious, which drives them to explore, but also territorial, which keeps them on a figurative leash.

There’s also a marked difference in wild threats to domestic cats. In the US, cats are vulnerable to pumas (also known as mountain lions and cougars), coyotes and a wide variety of birds of prey, from eagles, harriers and hawks to condors, osprey and even some larger species of owl. The UK does not have pumas, despite local legends to the contrary, nor does it have coyotes. Foxes, the smaller cousins of coyotes, and some birds of prey do pose a threat, but not to the extent that the wildlife of the Americas does.

For Graham, allowing his cats outside fosters their independent streak and allows them — or Bella, at least — to exercise their hunting impulses. Bertie isn’t known for his predatory prowess, but Bella is a pro at catching mice.

The local neighborhood is quiet, traffic is strictly limited to 20 mph, and the neighbors know each other well, often using their WhatsApp groups to track their kids in addition to cats.

In fact, if Bella could speak, Graham reckons she’d thank him for providing a home in a tranquil locale — and for never closing doors in their home.

What else would she say?

Graham says it’s obvious: “Glad that you understand the difference between my requests and my orders – you took a while.” She’d also likely chide the couple on their ineptitude as hunters, declaring Graham and Birch “are both rubbish at catching mice and rats despite how many times I show you how to do it.”

For Graham, the managing director of a London brand agency, and Birch, a skin care therapist, sharing their home with cats feels natural, and they cherish the unpredictable nature and playfulness of their feline friends. Cognizant of the fact that black cats are less likely to find homes, they prefer adopting melanistic house panthers like Bets, their previous cat, and Bella.

“I totally love all animals but as residents in our house, cats fit perfectly being clean, highly intelligent and able to manipulate any situation with an expression or display of love,” Graham says. “My favourite thing about Bella is when she surprisingly sits on my lap and the mystery when she hides in unlikely places causing me to rush around desperately trying to find her, not coming out even when I am shaking a treat bag.”

Bella will allow the game to drag out “until she decides to appear with her ‘I win’ look and swagger.”

Feline love is often hard-won, but that makes it worth it. In discussing Bella, it’s clear Graham lives for the moments when the independent-minded kitty decides to let him know how much he means to her by sleeping at the food of the bed, playing her hide-and-seek games and climbing into his lap.

Bella and Bertie may not be regular lap cats, but that’s okay with Graham and Birch.

“So there you have it,” Graham said. “Two cats that come and go as they please with occasional signs of affection, but get nothing apart from permanent love and affection from us.”

Bella is serious about her food. Credit: John Graham

Bella’s favorite toy, fittingly, is a mouse. Credit: John Graham

Spending time outdoors is important to Bella.