According to her daughter Liudmyla Melnykova, Tatiana Plachkova and her husband Oleh Plachkov were abducted on 25 September 2023. "People with assault rifles in special-purpose uniforms burst into our home, put handcuffs on my parents, took their phones and documents, and drove them away. They locked my grandmother in a room and ordered her not to leave," recounted Liudmyla Melnykova. The abductors did not conceal that they were from the FSB. They were particularly interested in Tatiana's Ukrainian phone number and the Telegram account on it. During the search, the Plachkovs were beaten.

The family did not receive any official notification of the detention. According to Liudmyla, her parents were held in basements in a factory, where partitions had been set up to hold people. According to testimonies of other captives, conditions in detention were cold, there was a lack of food, clothing, and medical care, and people were tortured.

Tatiana Plachkova was charged with "espionage" (Article 276 of the Criminal Code of the Russian Federation).

Before the Russian Federation's full-scale war against Ukraine, Tatiana and Oleh Plachkov owned two cafés in Melitopol and ran their own business. After the occupation of Melitopol, the couple decided to remain. There were several reasons for this: their elderly parents, responsibility for their employees, and a belief in a swift de-occupation. One of the pro-Russian Telegram channels posted that Tatiana was donating to the Ukrainian army. Subsequently, this became the basis for the "espionage" charges – allegedly cooperating with the SBU and passing on information. The so-called investigator did not allow Tatiana's mother to see her and did not permit her transfer to another hospital. The Russian authorities provided Plachkova with a "state lawyer," Olena Shapovalova from Melitopol, who before the full-scale invasion of the Russian Federation belonged to the Bar Council of Zaporizhzhia Oblast. According to media reports, she switched to the side of the Russian Federation no later than January 2023 and headed the occupation regional bar association of Zaporizhzhia Oblast. The "espionage" case was officially opened only after Tatiana's hospitalisation, there was no trial; some time later the case was closed. The pseudo-lawyer Olena Shapovalova ceased communicating with Plachkova's relatives after her death.

On 8 February 2024, Tatiana was brought to Melitopol Hospital No. 1 in a comatose state. "The woman caught influenza A. Due to severe systematic beatings to the head and regular torture, her condition deteriorated severely. By the end of October 2023 she was vomiting frequently, and subsequently stopped eating and drinking entirely. All requests, both by Tatiana herself and by her cellmates, for medical assistance to be provided to her were completely ignored. In December she fell into a coma, and only after the New Year holidays, on 10 January 2024, did the occupiers take her out of the basement in an unknown direction. Where the woman was located from 10 January until the beginning of February can only be guessed," recounted Zarema Bariieva, a human rights defender from the Crimean Tatar Resource Centre. The family attempted to obtain permission for transfer to Ukraine – they appealed to the Red Cross, various agencies, and wrote to the FSB. Permission was not granted. Liudmyla appealed to the ICRC with a request to monitor the provision of medical care to her mother, but the organisation stated that it had no access to the temporarily occupied territories. On 23 May 2024, Tatiana Plachkova died at Melitopol Hospital No. 1. In the documentation of her death, the Russians stated that Tatiana had pneumonia, pulmonary oedema and cerebral oedema, but the underlying causes of this condition were not reported.