64.

xamining the cigarette butts, you discover traces of fine Arabian tobacco and a faint aroma of Alexandrite ginseng. The only cigarettes you know that match that particular combination are Hookah Nails, a brand only sold at the Hookah Mart on the opposite side of the river. These teenagers were apparently bored Bostonians looking to slum it in Cambridge, and something about that riles your feathers. “Egads!” you think to yourself, “I need a magnifying glass if I’m to continue this course of detection.” Riley’s Discount Detective Gear is nearby, and probably is within your budget.

To go to the other side of the river, go to 55.
To go to Riley’s Discount Detective Gear, go to 25.
To go home and read The Sign of Four, an actual good story, go to 10.