They are Chicago’s frontline ambassadors, doling out nuggets of knowledge that burnish our reputation as the birthplace of the skyscraper. But becoming one of the Chicago Architecture Foundation’s 400-plus volunteer docents is not for the intellectually timid. Joining this hypercompetitive crew requires commitment: an in-person interview, nine weeks in the classroom, and field training that rivals only the dragon battle from Game of Thrones in intensity.

Any docent worth his or her red shirt can explain the difference between an arch and an apse. They can prattle on for hours about the legacy of Louis Sullivan. And they love to share arcane facts (“What’s used to clean the Chicago Cultural Center’s Tiffany glass dome? Horse shampoo!”). What they aren’t crazy about—along with having to scream over street musicians—is being told to speed things up.

It’s just after lunch on a Thursday in early April, and instructor Paul Meyers, a stout guy with salt-and-pepper hair and bushy eyebrows, is standing at a lectern in a glass-walled classroom in the lobby of the Santa Fe Center at 224 South Michigan Avenue. He’s working hard to convince the room of 40 or so veteran docents that the newest walking tour, Historic Treasures of Chicago’s Golden Age, can be completed in 90 minutes. (A similar tour it’s replacing clocked in at two full hours.)

“Do we get to wear roller skates?” asks a wisenheimer in a blue polo shirt.

Time is ticking. The CAF still needs 60 more docents to lead this tour, which is expected to be a top seller. Its launch will coincide with the opening this summer of the foundation’s new headquarters in the Mies van der Rohe building at 111 East Wacker Drive, itself a modern classic. Meyers shrugs off the heckling and starts to discuss in detail the City Beautiful movement, which flourished from the 1890s to the 1920s and will provide the storytelling muscle for this tour.

“Shouldn’t we be discussing the Pullman strike?” asks a guy in his 60s.

“Well, this is not a social history tour,” Meyers says. “You can’t ignore that there were major challenges. But what we want to focus on is the possibility and sense of accomplishment. And let the buildings show it.”

The meat of the day’s training is an on-the-street demo of the new tour. Joan Johns, a white-haired former stockbroker, leads the way. I struggle to keep pace as I join four other docents, all of whom are learning to lead this tour themselves. Stopping an inch from a spilt milkshake, she delves into an engrossing bit about the Chicago Athletic Association Hotel, at 12 South Michigan Ave.

Watching Johns, I see many of the “audience engagement” tactics from the classroom put to use. The building is framed perfectly, just over her shoulder. She maintains good eye contact. And she ends her spiel with a juicy tidbit: William Wrigley borrowed the familiar C from the CAA logo, which is plastered over the entrance, to use for the Cubs.

Over the rest of our 90 minutes, we soak in dozens of highlights. We visit the handsome lobby of the Palmer House, where Johns doles out advice on how to incorporate hotel magnate Potter Palmer’s role in the development of State Street. We analyze the exterior of the old Marshall Field’s building, which was constructed in multiple sections.

While cutting through the inside of the department store, I ask Johns if she’s ever left a guest behind. “I heard a story about one docent who lost someone right here,” she says, pointing to the cosmetics area. “The woman decided to get her face done at the makeup counter.”

The tour ends at the Cultural Center. Johns points out inscriptions in various languages along the walls of Preston Bradley Hall. But then my attention fades. I stare out at the lake. This is unfortunate. Because before I leave, the CAF asks me if I’d like to give a portion of the tour to a group of docents myself. And this building is my assignment.

Two weeks later, at the Palmer House Hilton, I meet another group of four docents who are learning the new tour. Joining us is Leslie Clark Lewis, a stylishly dressed woman who will judge our performances. If the docents nail this, they have one more hurdle: a full one-on-one tour with a trainer.

Me, I’m doing this for fun. Still, as we take turns giving the opening greeting, I start feeling a little intimidated. One longtime guide, Tom Carmichael, is wearing a pin that proclaims him “Outstanding Docent 2017.”

Tina Feldstein, a commercial real estate broker, bravely kicks things off. But her attempt to use the peacock insignias around the interior of the Palmer House as a point of interest falls flat. “I’d ditch that part,” Lewis says. Lucky for Feldman, today doesn’t count. “I’m still trying to find my theme,” she admits.

We head to the Cultural Center. Twenty minutes later, it’s my turn. Standing on Michigan Avenue, I glance at my notes and launch into my presentation. I point to the limestone façade. I remark that this gorgeous building once served as a library—a palace for the people, indeed. I even remember to mention that my 70-year-old mother-in-law studied here when she was in college.

I’m feeling pretty damn good—that is, until a woodchipper fires up in Millennium Park. Frazzled, I bluff my way through a section about how Jane Byrne supposedly saved the building from destruction. I end with an anecdote: Amazon leaders visited Preston Bradley Hall when they were scouting Chicago for HQ2. I make what I think is a clever connection by mentioning that Montgomery Ward, the trailblazing catalog giant of yore, once had its headquarters down the block. (An admission: Violating CAF rules, I used that tale even though I had no idea if it was true.)

So how did I do?

“Well, you had some factual errors,” says Lewis. Jane Byrne had nothing to do with saving the Cultural Center. “And you did something we try not to do: You talked about the interior before we were there. But that’s OK. It was good for you to give it a shot.”

Come retirement time, it looks like I might have to consider becoming a Walmart greeter instead of a docent. It might not be as prestigious. But at least that job pays.