Carriage Lamps: The Lock That Tells You a Whole Row

The train in Escape the Night Train has nine carriages, five chambers each, and it runs forward from the Observation Car to the driver's cab. Its new lock is Carriage Lamps: a lamp at the end of a row shows the total of every brick in that row. Every brick is still the sum of the two below it.

A row total is a free clue

A lamp gives you a sum for a whole row, so one missing brick in that row simply falls out. Here is a made-up example in the spirit of the lock.

A check you can use

Here is a little fact that lets you check a lamp: the total of a row is always twice the total of the row below, minus the first and last bricks of that lower row. In our example, 2 × 19 − 4 − 8 = 26, and the row above does total 11 + 15 = 26. If your numbers do not fit, something is off.

That works because each brick of the lower row is counted in two bricks above it, except the two on the ends, which are counted once.

More about the book

The book ends with a meta-puzzle, the Lamp Board, a six-row board of lamps with six lantern slots. The story is about the conductor's keys and a barn owl called Wink who has a nest in the cab.

How a page looks in the book

A low-resolution page from Escape the Night Train, so you can see the layout. Nothing on it is solved.

Books mentioned

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