Below it, in a different hand, someone had written: “λ̇ = 2.147. You’re welcome.”

The next morning, he called in the ringleader: a quiet, bespectacled student named Leo Kim. Leo had a 3.9 GPA and never spoke in class.

“It’s called the Geankoplis Gambit,” Leo said quietly. “My grandfather taught it to me. He was a process engineer at Dow in the 70s. He said the third edition has a hidden layer.”

Leo continued. “You know how Geankoplis sometimes skips steps in the example problems? How the answers in the back are just… final numbers? Grandfather realized that if you back-solve the example problems using the actual physical constants from the 1977 CRC Handbook (not the rounded ones Geankoplis used), you get a master set of correction factors. The lambda-dot is a mnemonic for the iteration sequence.”