The Greenpoint YMCA was overflowing with super heroes, witches, fairy princesses, and mad scientists at the annual Halloween party, one of the Greenpoint YMCA’s most popular free family events. Open to all members of the community, this year’s party had a “Mad Science” theme. Over 450 young people and their families were able to explore a 10-foot portable star lab, a haunted science lab and make their own slime.