Nikomedes was a aide the consuls of Nova Annonica, a hidden city, the only source of life on a dead moon orbiting the world they used to live on before the coming of the Serpent Gods. According to legends they are the last remnants of a grand empire, one whose history and the names of the true gods lost in the struggle. Things would have been much like they were until one day a strange vessel found the city. It was a scout ship of the Tok'ra, whom found the city by random chance while looking for a new base. Curious about the city (a curiosity that grew greater since the people within seem to have no understanding of how the city was built or even survives) the Tok'ra revealed themselves. While leery of this strangers whom resembled the Serpent Gods the consuls soon decided to make an alliance with these people in order step out of hiding and finally defeat the Serpent Gods that brought them low so long ago. Among the offer of alliance as the need for hosts, Nikomedes, filled with wanderlust volunteered.
Kal'Shek is a healer amongst the Tok'ra, a rarity due to the healing powers symbiotes. However given how operatives can risk great harm to themselves, it is not a rare things for one to return with injuries so severe that the symbiote alone is not enough. Kal'Shek was noted to be an excellent healer, being able to administer life-saving procedures no matter the circumstance (on event was saving a life while evacuating a base). Kal'Shek host was dying when the discovery of Nova Annoncia, and was the first to meet the potential hosts. At first he was leery of Nikomedes, a first seeing him as unaccomplished in life and superstitious (believing in nameless gods). However he was won over by the mans charisma and drive and so consented to the blending.
The blending was a success and both host and symbiote benefitted. Nikomedes now has new purpose and drive, bring the desire to end the Serpent Gods to full force. Kal'Shak has found that Nikomedes charms has improved his bedside manner and connecting to patients better. Together they while end the Goa'uld.