0 sick (in the way one shows his/her excessive interest in death, disease, cruel acts etc) -- morboso
his morbid fascination with horror films
her morbid imagination.
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Possiamo completarlo passo dopo passo, indipendentemente dalla lunghezza della strada, e non può essere completato, per quanto breve sia la strada, se non segni nemmeno la tua impronta.