New York City is full of lonely hearts seeking the right match, and what Alice, Robin, Lucy, Meg, Tom and David all have in common is the need to learn how to be single in a world filled with ever-evolving definitions of love.

In Manhattan, a bike messenger picks up an envelope that attracts the interest of a dirty cop, who pursues the cyclist throughout the city.

After a former elite agent rescues a 12-year-old Chinese girl who's been abducted, they find themselves in the middle of a standoff between Triads, the Russian Mafia and high-level corrupt New York City politicians and police.

After two tours of duty, Joe's life unravels as he waits for PTSD treatment.

On the hottest day of the year, an unknown virus spreads throughout inner-city Philadelphia. The infected victims, crazed by dehydration, begin attacking other residents of the neighborhood in gruesome ways. When the military is brought in to contain the situation, but realize they can't come up with a vaccine quickly enough, they fence off the area and let everyone die. A group of locals, stuck in the basement of their building, behind the fences, and separated from their family members, band together to try to survive.

Ever since her father drilled into her head that monogamy isn't realistic, magazine writer Amy has made promiscuity her credo. As much as she enjoys an uninhibited life free of commitment, Amy is really in a rut. While writing a profile about charming and successful sports doctor Aaron Conners, she finds herself actually falling in love for the first time -- and what's more, Aaron seems to really like her too. Amy starts to wonder if it's time to clean up her act and face her fears.