From 1920 to 1927, he served at the Danilov Monastery, serving as the closest assistant to Archbishop Theodore (Pozdeevsky), who headed the "Danilov" section of bishops, which included approximately 15 people. Father Seraphim's primary obedience at the monastery was working with youth. He was well educated, particularly in dogmatics and patrology, and led a highly spiritual life.
In 1927, he was arrested and sentenced to five years of exile in the Northern Territory. From 1927 to 1932, he was exiled to the town of Obdorsk in the Yamalo-Nenets Autonomous Okrug. Released in 1932, he lived in the town of Vereya and the village of Dorokhovo near Moscow, ministering to catacomb Christians in Moscow and Kirzhach. In 1941, he lived in the village of Tuchkovo near the glass factory.
After the arrival of the German army, he received permission from the occupying authorities to return to his homeland, where he traveled accompanied by his cell attendant, Nun Lydia (Gavrilova). On his way home, Father Seraphim tried to serve in every church he encountered, but the condition for his service was always that the priest in that church not belong to the Moscow Patriarchate. Thus, for the rest of his life, Father Seraphim never served alongside priests of the Moscow Patriarchate.
With great difficulty, they reached their village via Kyiv and Zhitomir. From 1942 to 1944, they were under occupation. After the war, Father Seraphim continued his secret prayerful labors, but a priest of the Moscow Patriarchate assigned to serve in these areas learned of it and reported it to Patriarch Alexei I (Simansky) in Moscow. After this, in 1945, he was immediately arrested by the NKVD in the Carpathians. He was brought to Kyiv and then transported to Moscow's Lubyanka. After numerous interrogations and abuse, he was sentenced to death by firing squad. After some time, the sentence was revised and he was given a 10-year prison sentence. From 1945 to 1953, he was imprisoned in Kraslag (near Mezhevo).
His collection of 35 letters to his spiritual children from the camp and exile is well-known. In 1960, he was tonsured into the Great Schema with the name Daniel. He died in Moscow on February 14, 1970, and was buried at the Kotlyakovskoye Cemetery. In the early 1990s, his remains were exhumed by monks from the Danilov Monastery and transferred to their monastery. This once again demonstrates how the Moscow Patriarchate appropriates the memory and holy relics of the True Orthodox ascetics, attempting to create the impression among the people that the Catacomb Church (True Orthodox) and the Moscow Patriarchate are indistinguishable.
Source: https://true-orthodox.narod.ru/photoalbum/second/Daniil.html