Conversation so far:
when did horslips return?
In March 2004.
Where had they been?
CANNOTANSWER.
what did they do after they returned?
Horslips returned to the studio in Westmeath to produce a studio album, Roll Back, in the summer of 2004.
was the album a hit?
CANNOTANSWER.
Are there any other interesting aspects about this article?
The exhibition moved to Belfast in February and March 2006.
what exhibition was there?
In March 2004, three Horslips enthusiasts, Jim Nelis, Stephen Ferris and Paul Callaghan, put on an exhibition of Horslips memorabilia in The Orchard Gallery in Derry.
was it a popular exhibition?
In February 2008, the exhibition opened in Ballinamore in County Leitrim, and in July it opened in Ballybofey in Donegal.

Question: what else did they do around this time?
Self-contained rewrite: Other than the exhibition, what else did the Horslips do around the event