This is one of the four lost serums, although in 'The Black Book of Buried Secrets' on Annie Oakley 's founder story a decoded code, says "Protect The Serum". The other four are the Lucian, Janus, Ekat, and Madrigal serums. The Tomas serum is the hardest serum to make online because it has the most clues in it. The only known people to have taken it are Thomas Cahill himself, Shaka Zulu, and Henry Francis Fynn. Others have taken it due to when Shaka Zulu took the serum. In the first series no team encountered it alone, like the Ekaterina Serum.