There are four sentinels, two mated pairs, in the pack. Each pair is specially chosen by the alphas and betas. The alphas and betas train the sentinels to take their places if anything should happen to them. The sentinels, since becoming one can start as early as one year, don't usually have authority over the pack unless the alpha or beta have publicly given it to them. They are respected though. Messing with a sentinel is messing with the alphas and betas themselves. This rank cannot be challenged whatsoever.
