5 details you might have missed in season 7, episode 7 of 'Outlander'

As viewers learned in previous episodes this season, Roger (Richard Rankin) has begun recording everything he and Brianna (Sophie Skelton) know and suspect about time travel for their young children in case they ever choose to travel back in time.

The couple's concern when Rob Cameron (Chris Fulton) takes off in the night with the notebook, along with their son Jemmy (Blake Johnston Miller), becomes apparent when Roger reveals that he has written extensively about the theory that travelers need a blood sacrifice to get through the stones.

The contents of the book aren't discussed at length but in chapter five of "An Echo in the Bone," the seventh novel in Diana Gabaldon's "Outlander" series, there's actually an outline of what Roger has written down at the time of Jemmy's kidnapping:

We learn that Roger's uncertainty about whether to include a chapter on blood is because while Claire (Caitríona Balfe) dismissed the necessity of a blood sacrifice for travel as a pagan superstition, he witnessed Geillis Duncan's (Lotte Verbeek) ceremonial slaughtering to get through the stones.

When Jemmy returns from school and proudly displays his pin badge declaring he is now a member of the Tufty Club, Roger is thrilled, as he was a member of the very same club as a young boy.

In fact, he told Brianna all about it back in season five, episode two, when the pair were first getting to grips with the idea that they would have to hunt for their food in the 18th century.

Expressing his reluctance to shoot a helpless squirrel, he remarked, "It's like shooting at Tufty Fluffytail," which drew a blank look from Brianna

"Should've known that reference would be lost on my American wife," he continued. "Tufty is a squirrel who teaches children about road safety. Sort of like your Smokey the Bear. Sort of, but there are clubs."

"Wow, sounds exciting," Brianna responded sardonically, not quite on board with the idea.

As viewers saw at the end of episode six, Jamie (Sam Heughan) was propositioned to join a group of riflemen led by Captain Daniel Morgan (Barry O'Connor) after the Welsh-born American soldier remarked on Jamie's aim and accuracy with an arrow.

Jamie agreed, postponing his return to Scotland once again, and in this episode, we see him kitted out in the same outfit audiences saw the captain wearing.

According to the American Battlefield Trust, Morgan and his men wore all wore the distinct white fringed garments, known as hunting shirts, to not only identify themselves but to strike fear in the British Army, who were aware of the riflemen's expert marksmanship.

Per the Museum of the American Revolution, the shirts were thought to evoke the dress of Native Americans. Not only that, but as the riflemen's reputation spread, General George Washington decided to outfit thousands more American soldiers in these distinctive shirts because of the psychological advantage it gave them over the enemy.

It's hard to overstate just how popular Phil Collins' debut solo single, "In The Air Tonight," was upon its release in 1981. It rapidly ascended through the music charts, rising to No. 2 on the UK singles chart and peaking at No. 1 in many European countries.

The use of the futuristic rock-synth song in the scene feels a little unexpected, but if you think about it, it's actually a rather fitting choice to accompany the first intimate moment we see between Brianna and Roger since traveling back to their own time period.

It's worth remembering that they initially left in 1971 — a whole decade earlier — when the world was a very different place. Across the 10 years that passed while they were away, there were huge leaps forward in technology, music, and culture, with "In the Air Tonight" encapsulating that.

All season long, William Ransom (Charles Vandervaart) has been looking forward to joining his fellow soldiers on the battlefield, and in this episode, he was finally able to, taking part — alongside fellow soldier, Sandy Hammond (Henry Ashton) — in the first Battle of Saratoga.

However, his first taste of battle leaves a sour taste in his mouth as he comes to understand the brutal reality of what it means to fight in a war, namely that either he or the men he has come to grow fond of, will inevitably perish.

When Sandy becomes the first soldier to fall, having been shot through the head by a sniper, William is momentarily stunned and never fully regains his composure until after the fighting is done.

It's a heartbreaking moment that harks back to Jamie's own time fighting on behalf of the redcoats in season five, which put him in opposition with his beloved godfather, Murtagh Fraser (Duncan Lacroix), with the latter sadly dying in his arms.

Afterward, Jamie decided to never fight for the British army ever again, which suggests that William could quite possibly find himself doing the same. Especially if the upcoming second Battle of Saratoga forces him to fight against Jamie, Young Ian (John Bell), or any of the other rebel friends he's made.

Episode seven of "Outlander" season seven is now available to stream on Starz.com, and also airs at 8 p.m. Friday on Starz.