At the outbreak of the First World War, Eddington is appointed chief astronomer at Cambridge by Sir Oliver Lodge and instructed to research Einstein's work and defend the Newtonian status quo.

Meanwhile, Einstein is lured back from Zürich to the Prussian Academy of Sciences in Berlin in an attempt to aid the war effort by embarrassing Britain by disproving the work of its great scientist Isaac Newton.

He then presents his lecture to his fellow astronomers at the university—defending Newton, but still thinking Einstein might be right—and takes the German Müller family into his home after saving them from a violent anti-German mob.

Realising that Mercury's orbit is precessing slightly more Tests of general relativity than it should be according to Newton's laws, he writes to Einstein despite the ban to inquire into his view on the problem.

Eddington realises he can prove that space and light are being bent by observing the solar eclipse of 29 May 1919 on the west African island of Príncipe, and with Dyson as an ally, manages to gain funding for his expedition, despite Lodge's initial opposition.

Einstein And Eddington is written by Peter Moffat and directed by Philip Martin, who both collaborated for the production of Hawking, a BBC biopic about the physicist.