Miranda Hart delivered some disappointing news on her Call the Midwife status.

The actress took to Twitter on Thursday to announce that she will not be part of the British drama in the sixth season due to work commitments.

She added that as sad as she is to not return, fans are "in for a treat" with new character Harriet Walter as Sister Ursula.

With characters dealing with new issues on the series, it sounds like Ursula will have quite an influence on everyone. Writer Heidi Thomas dished to Radio Times on what fans can expect.

"It's back to earth with a bump for our beloved midwives as they return from their magical Christmas mission trip to South Africa," Thomas said. "It is now 1962, and in a rapidly changing world, the arrival of Sister Ursula- superbly played by Dame Harriet Walter- brings new challenges to Nonnatus House. Tears are shed, and bonds reinforced, as the team pull together as never before."

Jenny Agutter, who plays Sister Julienne, previously told Bustle that everyone is going to embrace the future even with the challenges.

"Suddenly there is a new energy and everything that had been held back during the war- the science, the arts, the music- everything surges on," Agutter said. "So you arrive in 1961 and it is a brave new world. There is more available, the NHS [National Health Service] is established, and everyone is beginning to expect so much. There's more liberties, more freedoms, and with it comes greater responsibility and more choices."

Call the Midwife Season 6 is expected to premiere in spring 2017 on PBS.

Tags: Call The Midwife television PBS Miranda Hart