Just a possible scenario:

When King Tribhuvan exiled to India out of fear of Rana in 1950 along with his son Mahendra, he left behind his grandson Gyanendra. Rana, in order to maintain tradition put King Gyanendra on the throne and accepted as a King.

Is it possible that, King Gyanendra is forced to go into exile by Maoist with his son Paras, as they are the most unpopular figure in th country and grand son Hriendra is crowned as a King.  

This situation will solve many problems: It will make happy to a majority of people who want to keep monarchy in some form, it will provide a reason to Army and foreign powers to support the Maoist led governenment, it will also satisfy a section of Maoist who are only against Gyanendra and Paras as they have repeatedly said that their was some kind of coordination with Palace in the past. King Gyanendra and Paras will be OK upto an extent as they will have saved Monarchy from completely dead situation and hope for a better future and expect change of people's feeling about them. Prachanda will be happy as he will be another Jang Bahadur with head of state and government as he had said once that Nepal will have either Jung Bahadur or Buddha. One more thing, this scenario will forced the Maoist to accept multiparty democracy as authoritarian communism and monarchy cannot co-exist .

I think, history is repeating itself for a reason and this could provide a win win situation for all the parties involve and possibly lead to a peaceful solution.