 Complete the following phrase:  On 4 September 1939, during the German invasion of Poland he reported to the Communication Battalion of the Polish Army in Zegrze as the reserve plutonowy. Two weeks later, on the first day of the parallel Soviet invasion of Poland from the east, he was arrested in the village of Kołodno near Zbaraż and shipped to a Soviet POW camp. After two months, on 13 November 1939 Ząbecki was transferred to German jurisdiction in accordance with the Nazi-Soviet pact. He was sent to Parchim in Germany where he worked as a slave laborer on a farm in Klinken. He was released on 29 March 1941 for medical reasons and returned to Sokołów. Being a railwayman from before the invasion, he was put to work at the nearby Treblinka station on . There he secretly joined the resistance under the nom-de-guerre Dawny the old-timer in Polish and was asked by the Armia Krajowa AK to keep a watch on the German rail transports passing through the station. This intelligence became crucial following 