THE NITTY GRITTY:

Read about the Berlin Pass online at www.berlinpass.com. Sold with a Travel Card, two-day passes are (all prices in euros) 109 for adults and 59 for children. Three-day passes are 138 and 75. For more about Berlin, visit the English language site at www.visitberlin.de/en.

BERLIN — When the phone rang, it was the call I’d always dreaded. A family emergency canceled my long-planned trip to Berlin, putting my Berlin Pass (paid for in advance on the internet) in jeopardy, along with a nonrefundable airline ticket. Ouch!

Then came the brainstorm. I decided to offer the Berlin Pass to my cousin from Norway, Steven St. John, on the condition that he’d use it to see the city, take notes and tell me what he thought. After all, we’re different kinds of travelers, with different points of view.

He’s an economist who squeezes sightseeing in on long weekends. I’m a sidewalk-pounder, a people-watcher, a museum maven never loathe to strike up a conversation with a stranger. I know what I think about city passes. What would Steven think?

I’ve bought a half-dozen passes over the last decade, usually in big cities such as London or Rome. When you pay up front, the way you do at an all-inclusive resort, everything after that feels free (even though it isn’t).

But city passes aren’t about saving money. They’re about easy sightseeing. No running out of cash. No standing in line. You go to the gate at a leisurely pace and are waved through past the crowds. It means seeing more, with less energy, including places you might not have even known about.

Then the weeks went by until one day, an oversized envelope arrived filled with pages of notes, too many to quote here. (Story spoiler: my airline ticket was eventually refunded, except for $100. And a close read of the Berlin Pass website says unused passes can be refunded within 30 days of purchase).

Meanwhile, it was fascinating, getting into someone else’s head. Here’s a brief look:

STEVEN ST. JOHN ON THE BERLIN PASS:

“Picking up our Berlin passes (Val bought hers) wasn’t hard, but it would have been a lot easier if I’d printed out the reservation form at home and brought it with me. I thought I’d go mobile and just show it to them on my smart phone, but their Wi-Fi connection was so weak I couldn’t open the screen. Eventually, after giving them your name and mine, the poor fellow at the desk made a call or two, the passes were issued and we were away.

Each three-day Berlin Pass came with detailed guidebook. It also contained a one-day train ticket (which we used to go to Potsdam) as well as a subway pass. This we used every day but it was unclear how it would be validated as people got on and off the train without ever showing their tickets.

It also included a three-day museum pass timed from the first museum entrance, a two-day pass for a list of other Berlin activities — the aquarium, a riverboat tour and bicycling, none of which we had time to use — and a pass for multiple rides on the Hop-On-Hop-Off tour bus.

Despite being jetlagged that first afternoon, we dropped off our luggage and headed to the Berliner Dom, Berlin’s largest and grandest Protestant Cathedral and the Hohenzollern Kaisers’ (think kings) family church. But when we realized that showing the Pass would start the time clock, and more in need of a walk than a museum, we skipped the cathedral and walked over to the Brandenburg Gate.

At this point, now long past our bedtime at home, we ran out of energy and stopped to ponder the map. Then what to our wondering eyes should appear but a cluster of tour buses parked no more than 100 feet north of the Brandenburg Gate. We found our bus, showed the Pass and climbed aboard for what felt like — at that moment — a magic carpet ride.

These sightseeing tour buses really highlight the way you see a city. We’ve used them in every large city we’ve been to, as there isn’t a better way to understand the layout and the neighborhoods in a relatively short time.

In addition to getting a decent view of sites and attractions that you might not have time to visit, the ride gives you a feeling for distances, a key to planning each day. Most of Berlin’s tour bus rides cost about 20 euros — I checked — so the Pass proved its worth immediately.

On Friday we walked to Checkpoint Charlie (the border gate between Berlin’s western sector and the Communist eastern sector during the Cold War) and the Mauer Museum, next door. Here we showed our Berlin Passes and were whisked straight past the ticket desk.

The museum, a collection of jumbled rooms, contains an equally jumbled but incredible assortment of clever devices and tricky ploys invented by East Berliners determined to escape to the West. One exhibit was a tiny car into which one enterprising young man squeezed his girlfriend.

Another desperate East Berliner had his girlfriend sew an American officer’s uniform, which he then wore while walking across to freedom. But there were odd items there, too, like the spacesuit worn by an American astronaut, donated by a grateful patron. I left thinking that when it came to desperation, it was the museum that desperately needed a professional curator.

In retrospect, the success we had with the Pass depended on the location of our hotel, a Marriott Courtyard property I’d picked at random, and only because I’m on its mileage program. Not until we’d gone out and walked around did I realize we couldn’t have been in a better place.

The hotel was in the southeast “Mitte” neighborhood, the city center redeveloped post-reunification — and a 10- to 15-minute walk south of Museum Island. We could walk everywhere we wanted to go and a subway and a bus stop were within a block.

Instead of going to just one or two museums, we decided on a brief visit to all five Museum Island galleries, with a view to finding a favorite for longer visits later. After a quick walk through the Berliner Dom, we toured the Neues Museum, and its Egyptian antiquities and prehistoric cultures

After lunch, it was on for a quick look at the Alte National Gallery’s collection of 19th century painting, and finally on for a longer stay at the famous Pergamon Museum, known worldwide for its Greek antiquities and Middle Eastern and Islamic art.

By the end of the trip I estimated that without the Pass we’d have spent at least $100 riding trains and entering museums, castles and other destinations. The only palaces that didn’t accept the Berlin Pass were in Potsdam, where cold cash changed hands for those wonderments.

In conclusion, I’d agree that the Berlin Pass — a single ticket for the 60 attractions listed in the guidebook — makes sightseeing a breeze. But you’ll get a return on your investment only if you stay in or near the city center. If my friends asked, I’d suggest a three-day Pass and four days in the city, with the last day free.

That’s what we did, spending day four strolling down the Under den Linden through old Berlin. You pass a couple of churches, then the Humboldt University, the Berlin Opera and the Russian, French and British embassies, all abutting the street on the way to the Brandenberg Gate, where we’d started. Walking beneath it, 20 feet from where The Wall stood for so long, we felt lucky we weren’t there then.