An international situation has just become more complicated with the news that a couple is currently being treated for Novichok poisoning, the same potent nerve agent used on former Russian spy Sergei Skripal and his daughter Yulia in Salisbury, England, in March.

Developed in the then-Soviet Union in the 1970s, the paralyzing compound – which can be absorbed through the skin – had been placed on the Skripals’ front door in what is widely considered to have been an assassination attempt by the current Russian state security agency.

After several months in the hospital, both Sergei and Yulia have recovered, but many questions about the perpetrators and their motives remain. Now, the plight of civilians Dawn Sturgess, 44, and Charlie Rowley, 45, of nearby Amesbury has unwittingly revealed that more Novichok may be out there. According to the BBC, it is theorized that they were exposed to the agent during a visit to Salisbury last week.

The incident began to unfold on Saturday, when paramedics were called to the couple’s home after Ms Sturgess appeared to have a seizure, foaming at the mouth and eventually collapsing. Later that afternoon, an ambulance returned for Mr Rowley, after he started rocking against a wall, sweating, drooling, and making strange noises, according to an account by his friend.

Police initially believed that Sturgess and Rowley were having an adverse reaction to illicit drugs, but on Monday, the couple continued to display worrying symptoms, prompting the hospital to send samples away for rushed laboratory testing. On Wednesday night, Scotland Yard’s counter-terrorism chief Neil Basu issued a statement confirming that the analyses came back positive for Novichok.

Novichok actually refers to a family of several Soviet-made binary nerve agents; toxins that are made by combining two compounds that are not harmful independently, and are therefore easier to smuggle and obtain raw materials for without arousing suspicion. Like other organophosphates, Novichoks are acetylcholinesterase inhibitors, meaning they block the action of the enzyme that allows muscles fibers to reset after a contraction, forcing them to stay locked in place. Buildup of acetylcholine in muscle tissue results in vomiting, sweating, seizures, delusions, and eventually, death by respiratory and cardiac failure after the lungs fill with fluid and the heart stops beating.

Obviously, a rigorous investigation has been launched, yet it is unclear as of now how the two civilians came in contact with the poison. Thus far, no tainted objects have been found, and government officials have advised the public to exercise caution but to not panic.

"The working assumption would be these are victims of the consequences of the previous attack or something else but not that they were directly targeted. That could change," security minister Ben Wallace said on air at BBC Today.

Speculation by chemical experts on whether or not Novichoks are even stable enough to harm humans after four months of exposure to the elements has been conflicting.  

Vil Mirzayanov, the Russian scientist who helped create Novichok, stated if any of the agent was placed elsewhere in Salisbury, it would have decomposed by now because it is unstable in damp conditions. Therefore, he believes that Sturgess and Rowley fell victim to fresh poison.  

But Dr Andrea Sella, professor of inorganic chemistry at University College London, told ITV that the chemical is not volatile, counter to what some have stated, and suspects that the agent could have lingered because the last several months have been particularly dry.