One of our preferred methods of killing time before a plane's departure time is getting a drink-though we once missed a plane because of this and were forced to spend the night in BWI. With no flights in our near-future and a slight yen for the atmosphere of departures and arrivals, we thought, Why not get a beer at the train station?, hoping to find the bustling, sometimes convivial atmosphere we've found at airport bars. So, without even a train to catch, we stopped in at the Java Moon Café after work one Thursday. We discovered a slammed bar. A diverse crowd occupied the plastic tables and chairs clustered in the small-ish space, immediately by the Charles Street entrance to Penn Station. A dreadlocked guitar player was strumming away, soon to be joined by a man with a djembe drum. Every barstool at the front was taken, and the pleasant-seeming bartender was contending cheerfully with a small crowd standing off to the side of the bar. (There is no table service.) Two flat-screens loom above the bar: One played the U.S. Open, the other read out train times. As we like to sit at the bar when we drink, we were somewhat discouraged and decided to try the Java Moon Café-actually an outpost of a New Jersey franchise-another time. We found ourselves back on a Sunday afternoon, waiting for a loved one to return from New York. The bar was dead. The weekend bartender explained that this, relentlessly, was the weekend crowd. But our $5 Loose Cannon was cold, and the midnight blue-painted bar, which had seemed rather lacking in atmosphere on Thursday, was sunny and clean. An elderly couple came in with bags, which they set down at a table. The man ordered a Shocktop and his wife asked for a seltzer with lime. "I just have tonic," the bartender replied. Disappointed, she ordered a water with lemon. "Do you have lime?" she queried moments later, as the bartender was filling her glass. "Yeah. . . . You want it all," he quipped. As he set down the water in front of her, we could smell the citrus from a plastic barstool away.