BEIJING -- Suddenly, bodies popped up out of nowhere. Boston Bruins forward David Pastrnak, shirt white against the ancient mountains splayed out in the distance, stood on top of a watchtower on the Great Wall of China.

Next to him, forward Jake DeBrusk appeared, a little warier, a little more tentative.

Pastrnak? He had no reservations, flinging his arms wide, as DeBrusk held on with both hands.

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"It was definitely (Pastrnak), for sure," DeBrusk said, of the instigator of the daredevil moves. "I'm afraid of heights. It was 100 percent him. By the time we were negotiating it, he was already up there. So I had to join him."

He would never have lived it down had he chickened out.

"He was totally terrified, like a little guy," Pastrnak said, smiling. "I haven't done it [before]. But I'm always like this, since I'm kid. I love heights and I love adrenaline, so anytime I can risk anything, I risk everything, every time."

And while Bruins general manager Don Sweeney would probably rather Pastrnak play it a bit safer, for the sake of his hair line and his heart rate, that's who Pastrnak is.

Video: DeBrusk mic'd up for Bruins' visit to the Great Wall

So it made sense he was the one hopping up onto parapets and jumping onto Brad Marchand's back for a piggy-back ride and downing a Tsingtao with some of his teammates at the top of the Great Wall on Sunday.

He was relaxed, his most ebullient self. So were the rest of the Bruins.

This was the Bruins embracing the moment, taking in a day at the Great Wall and wringing all the fun they could have out of it.

They were (mostly) stress-free, having finished with their first city and first game of the 2018 O.R.G. NHL China Games - a 4-3 shootout win on Saturday in Shenzhen, China - and able to enjoy a day of bonding and sightseeing before getting back to the grind on Monday ahead of their second game, Wednesday, in Beijing (7:30 a.m. ET; NBCSN, SN).

There were pictures taken on all the highest points. There were names signed to a graffiti board. There were toboggan rides down and gondola rides up and pictures taken -- for a price -- with costumed characters by backup goaltender Jaroslav Halak.

It was a workout and team bonding and history lesson all in one, even for those -- like Brad Marchand -- who decided to take on the Great Wall in flip flops.

"It's been pretty incredible just to be in a different culture, to see things that are so out of the norm, that's such a big part of history that very few people ever have the opportunity to do in their lifetime," Marchand said, sitting at a small cafe atop the Wall, squeezed next to Pastrnak on a bench.

"To be able to be over here with the group of guys that we have and to be able to do it the way that we do, it's been pretty special."

The anticipation started days before, with some research. Defenseman Charlie McAvoy, not long removed from his days at Boston University, looked up the Seven Wonders of the World, building his excitement for the trip. It had not waned as the trip neared its end on Sunday afternoon.

"I took a lot of pictures to show my family and my friends back home," he said. "It's amazing. I don't think the pictures do justice to coming here and being able to experience it, which this game allowed us to do. Because I don't think I would have been here otherwise. I'm fortunate for that. I'm fortunate to have gone with all these guys. I think it really does help build an even stronger bond."

This Bruins team is tight. It was a team that felt cheated out of a longer stay in the Stanley Cup Playoffs last spring, a team that believed it had been destined for more than it got, with an exit in the Eastern Conference Second Round.

But that was a bond that took time to build. It's a bond that's being rebuilt now, with every experience in China, every step on the Great Wall, every piggy-back ride.

"I don't know if he worked out or just ate all summer," said Marchand, who lost an unidentified bet to Pastrnak, resulting in the back-testing ride. "But he got a lot heavier."

It was easy between most of the players on Sunday, between the tight group of McAvoy and DeBrusk and Pastrnak and Marchand, between Brandon Carlo and Matt Grzelcyk and Ryan Donato, between players who have traveled 8,000 miles already this season and believe they have so much further to go.

"I think it's unique to come," McAvoy said. "If you're going to come over [to China] and be out of your comfort zone, it's a whole lot easier when you're with some of your best friends and you're with your group of guys that you feel extremely close with. So we all experience it together and it feels that much better, that much more comfortable when you come over here and you're with this group.

"I definitely could see it paying off in a big way."

It felt like the Bruins were building on Sunday. They were building a team. And, in doing that, they managed to have some fun, no one more so than Pastrnak. He might have been giving some of the Bruins personnel anxiety attacks, but he had one response to any concerns over his antics on the Great Wall.

"YOLO," Pastrnak said. "Absolutely YOLO."