The Hard Problem encores at Palace Cineplex and Palace Multiplex on Mother's Day.

The Hard Problem is Tom Stoppard's first play for the stage since Rock 'n' Roll in 2006, and his first for the National since his trilogy, The Coast of Utopia, 2002.

Hilary, a young psychology researcher at a brain-science institute, is nursing a private sorrow and a troubling question at work, where psychology and biology meet. If there is nothing but matter, what is consciousness?

This is the hard problem which puts Hilary at odds with her colleagues, which include her first mentor, Spike; her boss, Leo and the billionaire founder of the institute, Jerry.

Is the day coming when the computer and the MRI scanner will answer all the questions psychology can ask?

Meanwhile, Hilary needs a miracle, and she is prepared to pray for one.