Abel’s House of Secrets - Young Justice

A magic store operating in New York City, Abel’s House of Secrets was located opposite the residence of Billy and Greta Hayes. They could see the storefront through the broken fence of their back garden. 

The word “Secret” on the faulty neon sign was the last thing to be seen by Greta before Billy killed her.

When Greta's soul rose from the dead on October 31st, 2010, it was the only word she could say, leading Artemis and Zatanna to dub her "Secret." Once her ghost was laid to rest, the heroes realised, to their horror and disgust, the significance of the word.