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Recent spectroscopic observations of the [C <ns0:sc>II</ns0:sc>] 158 μm fine-structure line of ionized carbon (C+), using the Stratospheric Observatory for Infrared Astronomy (SOFIA), have revealed expanding [C <ns0:sc>II</ns0:sc>] shells in Galactic H <ns0:sc>II</ns0:sc> regions. We report the discovery of a bubble-shaped source (S144 in RCW79 in the GLIMPSE survey), associated with a compact H <ns0:sc>II</ns0:sc> region, excited by a single O7.5–9.5V/III star, which is consistent with a scenario that the bubble is still mostly “filled” with C+. This indicates most likely a very early evolutionary state, in which the stellar wind has not yet blown material away as it has in more evolved H <ns0:sc>II</ns0:sc> regions. Using the SimLine non-local thermodynamic equilibrium radiative transfer code, the [C <ns0:sc>II</ns0:sc>] emission can be modeled to originate from three regions: first, a central H <ns0:sc>II</ns0:sc> region with little C+ in the fully ionized phase, followed by two layers with a gas density around 2500 cm−3 of partially photodissociated gas. From these two layers, the second layer is a slowly expanding [C <ns0:sc>II</ns0:sc>] shell with an expansion velocity of ∼2.6 km s−1 that corresponds approximately to a bright ring at 8 μm. The outermost layer exhibits a temperature and velocity gradient that produces the observed self-absorption features in the optically thick [C <ns0:sc>II</ns0:sc>] line (τ ∼ 4), leading to an apparent deficit in [C <ns0:sc>II</ns0:sc>] emission and a low ratio of [C <ns0:sc>II</ns0:sc>] to total far-infrared (FIR) emission. We developed a procedure to reconstruct the missing [C <ns0:sc>II</ns0:sc>] flux and find a linear correlation between [C <ns0:sc>II</ns0:sc>] and FIR without a [C <ns0:sc>II</ns0:sc>]-deficit after incorporating the missing [C <ns0:sc>II</ns0:sc>] flux. This example demonstrates that at least some of the [C <ns0:sc>II</ns0:sc>]-deficit found in Galactic H <ns0:sc>II</ns0:sc> bubbles can be attributed to self-absorption, although a broader sample of these objects needs to be studied to fully constrain the range of conditions in which [C <ns0:sc>II</ns0:sc>]-deficits can be explained by this process.