understudy

An actor or an actress who takes the place of somebody else who can't take on a role in theatre production due to illness, vacation, or any other reasons.

Character - Played By
     Jack - Taylor
   Mother - Jaime
      Cow - Lilani
    Gypsy - Megan
   Vendor - Deedee
    Imp 1 - Lilani
    Imp 2 - Sarah
     Duck - Alayna
    Flute - Lea
    Giant - Jennifer

The understudies were organized so poorly that upon sickness (or death) of somebody, everything moves around due to one person not being able to be two characters on stage at once.

Who Dies: What Happens
  Taylor: Lee becomes Jack, Megan becomes Flute.
   Jaime: Lauren (Narrator. Somebody else will the narrate.) becomes Mother.
  Lilani: Deedee becomes an Imp and nobody(!) is Cow*.
   Megan: Sarah becomes Gypsy.
  Deedee: Jennifer becomes Vendor.
   Sarah: Deedee becomes an Imp.
  Alayna: Lilani becomes Duck, Deedee becomes an Imp.
     Lea: Megan becomes Flute.
Jennifer: Taylor becomes Giant, Lea becomes Jack, Megan becomes Flute.

Why couldn't Megan just replace Jennifer? Don't ask me. It's not a complicated part. Maybe she was too small, but I think she was taller than Taylor at the time.

And I don't even want to think about what would happen if two people got sick.

*The Cow is a simple (but evil) part that could easily be filled by Alayna but no understudy was officially designated.

Un"der*stud`y (?), v. t. & i. Theater

To study, as another actor's part, in order to be his substitute in an emergency; to study another actor's part.

© Webster 1913.

Un"der*stud`y, n.

One who studies another's part with a view to assuming it in an emergency.

© Webster 1913.