The play River (Stellan Skarsgård) goes to see in The Globe Theatre is The Comedy of Errors, an early William Shakespeare play.
Stellan Skarsgård (John River) & Alec Utgoff (Sasha Mischenko) also worked together on Our Kind of Traitor (2016) as Dima & Niki respectively.
Nicola Walker (Jackie 'Stevie' Stevenson) and Adeel Akhtar (Ira King) also starred together in Unforgotten (2015), as DCI Cassie Stuart & Hassan Mahmoud respectively.
Stevie was born in August 1971 (Leo or Virgo) so would have been 34 here. Nicola Walker was born more than 12 months before in May 1970 (Taurus).