The aim of the present study is to understand the nature of the second language acquisition process with regard to the writing skill in terms of syntactic complexity, accuracy, and fluency. The academic writing developmental path was followed over one academic year (six months) for each individual student included in a sample consisting of 10 Egyptian EFL freshmen. The correlation among syntactic complexity, accuracy, and fluency was also explored for each individual student. The ten cases were enrolled in a class in the Department of English language and Literature, Faculty of Arts, Cairo University. The research is a longitudinal multiple-case study. A mixed (non-experimental) exploratory design is adopted. Qualitative data, which were the students' written essays, were collected over one academic year twice a month (11 times). The results indicated fluctuation in the written performance of the cases. The cases did not progress right through. Seven developmental patterns were revealed for syntactic complexity, four for accuracy, and only one pattern was demonstrated for fluency. The correlations among syntactic complexity, accuracy, and fluency were found to be dynamic. For three out of the 10 cases, correlations turned out to be positive after being negative initially. For 7 out of the 10 cases, correlations turned out to be negative by the end of the academic year. These findings imply that dynamicity is the impetus power of language development, and exposure to language input and teaching does not directly transform into grammatically accurate or highly fluent complex language.