From a middle-class boy growing up in South Kolkata’s Naktala neighbourhood to Trinamool Congress secretary general and a minister in the Mamata Banerjee cabinet, Partha Chatterjee’s five-decade career had a chequered upward trajectory. But it appears to have taken a downward spiral, as the 69-year-old was arrested Saturday by ED in a “bribe-for-job” scandal from his stint as education minister.