Historically, this had been to the benefit of Boston, insofar as the river served as a moat to protect the settlers from the wilderness that lay beyond the outskirts of old Newtowne. But in modern times, the river’s boundary was a limiting factor, and surely Boston would have otherwise absorbed Cambridge long ago, as it had Brookline and Charlestown.Still, there was one place where even a river didn’t make a difference, where the cities kissed one another over a bridge so small few were even aware there was a bridge at all. The Boston Museum of Science sat at that point, on top of the river, with half of its exhibits in Boston and half in Cambridge. Not far beyond the museum on the Cambridge side was a large shopping mall, and a few blocks further, down the side of the river, stood two decent-sized towers. Thirty years earlier, neither the towers nor the mall existed—except perhaps in the imagination of a few development entrepreneurs—because back then the entire area was just unpleasant enough for Cambridge visitors to the museum to seriously consider approaching it from the Boston side to avoid any trouble.Corrigan Bain lived in a condo in the left tower, on the seventh floor.