We followed the girls (with their blessing!) to a hostel in the western part of the city, checked in, freshened up, and exploited wifi! The hostel owners agreed to do some laundry in return for a beer, which was a welcome prospect!
We walked back into town, perused a terrific flea market, and explored the Museum of Broken Relationships. Zagreb was once two warring towns. Following their formal unification in the 18th century forming the upper town they gave birth to the lower town, a sprawling delta of sequential superposed architectural styles. All Austro-Hungarian stucco in the middle and socialist concrete on the outskirts.
After lunch we met our Croatian colleague from Caltech B, with whom we explored the city and discussed linguistics, music, history, science, non-commutative topology, and of course the mysterious elephant trunk problem.
In the evening we retired to the hostel, said goodbye to B and L who were leaving early the next morning, and hit the sack ourselves.
Next morning after a late start we walked back to the train station. We were pleasantly surprised to run into L, the girl we met on the bus from Skopje to Prishtina. She was taking the same train, so we attempted to finish our earlier conversation.