Mariana, twenty-three, newly arrived from Caracas, held the book like a lifeline. Its cover was a vibrant, confident red. On it, a collage of smiling people—a businessman shaking hands, a woman laughing at a café, a family at a park—promised a life she didn't yet have. The title read: Interchange Fourth Edition Intro .

He pointed to a dialogue on page 47:

He pointed down the street. “Two blocks. You can’t miss it.”

The book had a special section at the back of each unit: the Interchange . It wasn’t grammar drills or vocabulary lists. It was an activity. You had to get up. Walk around. Talk to real people.