'Doctor Who' star helps grieving boy

Peter Capaldi, who plays the 12th incarnation of Doctor Who, sent a video message to a 9-year-old fan grieving the loss of his grandmother. "... You should know that we're on your side. So you look after yourself, take care and be happy."

When Benedict Cumberbatch wanted to share news of his engagement to director and actress Sophie Hunter, he kept it delightfully traditional. The announcement was made with nothing more than a six-line notice in the UK's The Times. Way to keep it real, Sherlock! Here are a few more moments when celebrities have stepped out of their reality and into ours.

Sir Ian McKellen had a laugh with some schoolkids in October. Invoking his "Lord of the Rings" character Gandalf the Grey, McKellen warned a gaggle of British students gathered outside a library window that they'd better buckle down. "If you don't do your revision properly, do you know what will happen?" McKellen said to his rapt audience. "YOU SHALL NOT PASS!" Cue the cheers, and extra points for McKellen for not being too famous to encourage young fans.

Is there a better surprise for a Trekkie than a visit from Patrick Stewart? The actor took some time out from his appearance at Atlanta's Dragon Con on August 29 to meet a fan named Dawn Garrigus. The young girl has mitochondrial disease and asked to meet Stewart through the Make-A-Wish Foundation. Stewart talked with her for a while, signed autographs and gave her a heartwarming hug.

Bradley Cooper wasn't just stopping by a London Burger King for a Whopper run on July 29. He was actually doing work -- and in more ways than one. According to E! News, the Oscar nominee got behind the grill and learned how to flip burgers for a role in an upcoming movie.

With the cancellation of Sarah Michelle Gellar's CBS show "The Crazy Ones," the actress has turned to less glamorous career options. On July 13, the mother of two joked that a lemonade stand was her newest way to bring home the bacon. "Got to earn a living somehow (right)?" Gellar tweeted, along with a snapshot of the roadside watering hole. (No word on how much she earned on the job.)

Taylor Swift should be invited to all of our parties. Not only does the superstar singer show up when called -- as she did when fan Gena Gabrielle sent the star an invite to her bridal shower in Columbus, Ohio -- but she comes bearing gifts. Gabrielle, pictured here with Swift on the day of her bridal shower, was gifted with plenty of cooking supplies from the singer, including a KitchenAid mixer.

Bryan Cranston has gone from "Breaking Bad" to Broadway, but the actor is happy to turn himself back into Walter White for a fan. While signing autographs after a recent performance of "All the Way," Cranston agreed to help one teen ask a girl to prom: "Maddy, if you don't go to the prom with Stefan," Cranston intoned, "then maybe your best course of action would be to tread lightly." Obviously Maddy must be a "Breaking Bad" fan, because she said yes.

After an online effort to make it happen, Jon Bon Jovi walked Australian bride-to-be Branka Delic down the aisle before her wedding to Gonzalo Cladera at the Graceland Wedding Chapel in Las Vegas on October 12, 2013.

Despite being one of the biggest celebrities around, Tom Hanks has a reputation for being a man of the people. Case in point: The actor quietly reported to jury duty in September 2013 before the case came to an abrupt end.

Dave Matthews gave one of his fans the experience of a lifetime when he hopped into the back of her car after his bike broke down on his way to a concert in July 2013. The fan, Emily Kraus, has said how kind Matthews was, inviting her and her boyfriend to dinner and giving them front-row seats to the concert.

Jay Z proved that he's not too famous for NYC's subway when he took the train to a performance at Brooklyn's Barclays Center in 2012. The artist chatted with another artist, Ellen Grossman, along the way.

Most celebrities will announce their presence months before they arrive anywhere, especially if it's an event that will bring them positive press. But when Tom Cruise gave a commencement speech last year to aspiring actors at Joanne Baron/D.W. Brown Studio in Santa Monica, California, he showed up completely unannounced. One source told the New York Post that it was "one of the most inspiring speeches we've had."

David Lee Roth is another celeb who can assist in an emergency. The rocker switched gears from music to medical help in 2004 when he worked as an EMT in New York.

Since her relocation to New York City, Katie Holmes has been seen taking full advantage of the city that never sleeps. Aside from frequently strolling the streets of New York like a regular Joe, Holmes was also photographed sneaking in a catnap on the subway in November 2012.

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• "We're on your side," actor Peter Capaldi tells fan grieving loss of his grandmother


• 9-year-old Thomas Goodall comes from a home of Dr. Who fans, or Whovians


• Thomas wrote a letter to Capaldi when he took over role from Matt Smith

(CNN) -- The past few weeks have been hard for 9-year-old Thomas Goodall, who lost his grandmother in early October.

It was the first major loss of a loved one for the autistic boy from North Baddesley, England, who relies on a consistent routine to avoid meltdowns, his father, Ross Goodall, said

Things finally began to take a turn for better on Monday, when Thomas received a comforting video message from actor Peter Capaldi, who plays Thomas' favorite TV character, Doctor Who.

For the first time since his grandmother's death, Thomas smiled.

"I think it probably meant everything to him," his father told CNN. "I think it gave him the emotional support that we as parents couldn't."

After Ross Goodall posted the video on YouTube on Thursday for family to see, others took notice and started sharing it, drawing more than 200,000 views in 48 hours.

It didn't come out of the blue. Thomas comes from a household of Whovians, where sonic screwdrivers, robot daleks and TARDIS time-travel machines make up much of the decor.

The fanaticism extends to Thomas' fashion choices. His signature outfit consists of a checkered shirt, suspenders and bowtie in honor of the 11th incarnation of the time-traveling doctor played by Matt Smith -- one of Thomas' favorite doctors. Other days, he wears a pair of Converse sneakers, 10th doctor David Tennant's trademark look.

When Capaldi took over the role from Smith in 2013, it was a big deal for Thomas, Ross Goodall said. To help cope with the change, Thomas sent Capaldi a letter in September letting him know that he looks forward to following Capaldi's adventures as the new Doctor Who.

Capaldi responded with a letter and autographed headshot. After Thomas' grandmother died, Ross Goodall reached out to Capaldi through his agent and explained that Thomas having a hard time dealing with the death of his grandmother.

Thomas meets former "Dr. Who" actor Colin Baker, left.

Again, Capaldi came through.

"Thank you very much for your letter. I really enjoyed getting it because, you see, when Clara and I are traveling around time and space, sometimes bad things happen to us. And, you know what, Thomas, sometimes sad things happen to us, too, so it's nice to know that there's somebody like you out there who's on our side, and you should know that we're on your side.

"So you look after yourself, take care and be happy."