The volunteer expected to find the keeper despondent when the pumps stopped. (despondent: disconsolate, dejected, disheartened) The old man was a stoic, though, and looked almost resigned to the flooded garden. (stoic: in this context uncomplaining soul, unflinching person; resigned: accepting, acquiescent, reconciled) His silence sounded defeatist to a young man certain that enough enthusiasm could resuscitate anything. (defeatist: pessimistic, resigned; resuscitate: revive, reanimate, restore)
A fatalist might have left. (fatalist: in this context believer in fate, believer in predestination) The keeper stayed, cleared a channel and let water out by the back gate. His steadfast patience was easy to misconstrue as pessimism. (steadfast: staunch, unwavering, resolute; misconstrue: misinterpret, misunderstand, misread; pessimism: gloom, gloominess, negativity) Indeed he was pessimistic about the roses; no one had bred a rose able to live under water. (pessimistic: gloomy, negative, doubtful)
The volunteer brought a shovel. Two days later the soil was wet but firm. The keeper's resolve had never faltered. (resolve: determination, resolution, resoluteness) He just knew when a pump was futile and an open gate could do some good. (futile: fruitless, vain, useless)