Seeing three shows constituting five hours of theater in one day sounds daunting. But there's something to be gained in watching Mixed Blood Theatre's "Center of the Margins" festival in marathon fashion. You can't do that during the week, but if you have a weekend day open, consider it. The three works, which explore disability, play off each in the mind and fill in the experience when seen in series.

Ken LaZebnik's "On the Spectrum" is the most successful piece in the festival. Jack Reuler directs this love story between two young people who are at different points along the continuum of autism -- a man with high-functioning Aspergers and a woman more profoundly autistic.

Mac (Skyler Nowinski) and his mother, Elisabeth (Regina Marie Williams), worry that they will lose their apartment because Elisabeth's work hours have been cut. Mac, beautifully focused and methodical in Nowinksi's portrayal, finds a job designing a web site for Iris (Laura Robinson). The real world, though, presents problems for Iris, who lives in a magical "Other World" she has created in cyberspace.

It's really Mac's story, how he affects and is affected by Iris. He tugs her toward the physical realm, while she feeds his emotional needs.

LaZebnik writes incisive, moving dialogue. Mac observes that autism awareness has risen at the same time the world has become more autistic, people hunched over their cell phones and computers and ignoring the real world. He's given us a glimpse of life on the spectrum and done so in a play about two kids just happy to love and be loved.

"My Secret Language of Wishes," by Cori Thomas, has at its core a sentimental personal story. But with twists, revelations and multiple plots, the play bites off more than it can chew in just under two hours. We are puzzled over who this play is about. Thomas ostensibly is writing about a custody battle over Rose, a young African-American who has cerebral palsy. The combatants are Dakota, a white woman who has been Rose's caretaker for several years, and Brenda -- rich, middle-aged and African-American. Alongside this story, Dakota's lawyer, Jo, is having relationship problems with Cecelia.

That this diffuse and maudlin scenario lands at all with an audience testifies to director Marion McClinton's production. Brittany Bradford brings amazing technique and emotional depth to Rose, and Taj Ruler's feistiness defines Dakota. But Thomas inserts too many people and too many vagaries, and her script avoids simple truths for the sake of stirring argument. Most significantly, Thomas's play makes Rose little more than a pawn, without giving her any agency.

If "Secret Language" is overwritten, Rajiv Joseph's "Gruesome Playground Injuries" feels underbaked. Dag (Nic Zapko) and Kayleen (Alexandria Wailes) portray friends who meet in the school nurse's office as 8-year-olds. The play jumps though time to points when the two intersect, always focusing on Dag's accidents or Kayleen's disorders. A repetitive rhythm makes the work feel long, and we never get a handle on the psyche of Dag, who courts disaster with reckless behavior. Kayleen is a bit more transparent -- the product of an absent mother and an abusive father. The mood of this staging, directed by Aditi Kapil, feels decidedly downbeat, and it's difficult to root for the two heroines.

Joseph wrote this play for hearing actors. Zapko and Wailes perform in American Sign Language, with text projected on a screen behind them. For deaf audiences, this isn't an issue. If you do need the text, though, you miss much of the actors' emotion.