Home to pretty treasures, Dumka is India's best kept secret. After your splendid visit to Dumka, you can proceed to an important near-by city of Agra. Attractions in Agra include Taj Mahal, Agra Fort, Fatehpur Sikri. Also, to reach Dumka, you'll have to take a flight to Agra; so its not really a detour. And even if it is, the city is worth paying at least a quick visit. Popular vacation packages of Dumka are of 1-2 days.
Yes,it is that simple really! Enjoy your trip! Keep travelling!