As PEOPLE reports in its new cover story, Cruise has been making several calls a day to his daughter Suri, 6, who lives in New York City with mom Katie Holmes, while he's been working long hours on his sci-fi thriller All You Need Is Kill since August.
"He misses his little girl," says his friend, screenwriter Christopher McQuarrie.
Meanwhile, often late at night once film work has wrapped, Cruise has relaxed over spirited dinners and occasional club nights with old and newer friends.
On Sept. 20, Cruise caught a late night dinner with actress Roma Downey and her husband Mark Burnett, who produced the MTV Movie Awards the year Cruise appeared as his Tropic Thunder alter ego Les Grossman.
The night before, he stayed out until 3 a.m. at the nightclub Annabel's, where Cruise hung out with friends including McQuarrie and his wife.
At Annabel's, a laid-back Cruise chatted up several fellow club-goers. "Tom loves the people here [in England]," says a source. "They're friendly."
Earlier in the month, Cruise caught his friend Mark Rylance in Shakespeare's Richard III at the Globe Theatre, and at the end of August he caught up with former girlfriend Penélope Cruz, husband Javier Bardem and his Knight and Day costar Cameron Diaz at a dinner in Coworth Park.
In between, there was a quick vacation to Hvar, Croatia, where he hung with Washington Redskins owner Dan Snyder, a past investor in Cruise's production company, and his wife Tanya.
But there's no new romance in his life yet: Three months after Holmes filed for divorce, Cruise isn't ready to date again, sources say.
"When he's in London he's going to be seeing his friends," says a source. "[But] there is no mystery woman."
With reporting by PHIL BOUCHER AND JD HEYMAN