Adam Cross

"So sad a man died this way...and yet so amazing."

- Jemma Simmons speaking of strange way in which Adam Cross died

Adam Cross was a firefighter who aided in the aftermath of the Battle of New York. He and fellow firefighters found a Chitauri helmet that they kept as souvenir. Unbeknownst to the group, the helmet carried a virus which causes those who contract the virus to die in a very strange way. Cross eventually contracted this virus and was killed.

Biography
Cross and fellow firefighters found a Chitauri helmet while helping aid in the aftermath of the Battle of New York. Months after the Battle of New York, Cross and some fellow firefighters decided to polish the helmet. The helmet carried an alien virus which Cross contracted. Cross volunteered as a scout leader, and while out with the scouts, he began to feel the effects of the virus, and was eventually killed by it. The virus causes the body of the victim to float after death, which is what caused Phil Coulson and his team to investigate the killing.

While Jemma Simmons was investigating the body of Cross, and spark jumped from Cross to Simmons. Simmons did not even realize at this point that a virus had caused the death of Cross, much less that the virus traveled from body to body via a spark.