Twice Sold Tales just off Broadway on Capitol Hill has a ton of books--the science fiction section usually has a great selection.
The cat bridges above your head are novel but the cat boxes stick even though they are cleverly disguised.
The staff/owners has/have often been rude but then the next time almost friendly. They do seem at least to know what they ahve if you ask for a specific book.
And they are open pretty late.
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