Capacitor discharging
If capacitor is connected to a closed circuit it will either charge or discharge, depending on the voltage "forced" on it (the equilibrium or steady state voltage, that is reached when there is no current flow through the capacitor). If this voltage is higher than the capacitors \$Q/C\$, such as with case when it is connected to a power supply, it will charge to reach this voltage. If there is no voltage source, or it's voltage lower than \$Q/C\$, the capacitor will discharge to reach this voltage as well. In case of passive elements only this voltage would be \$0\$. So the capacitor will act as a power source, and the current will "go" into capacitor itself (in order to equalize the charges on the capacitor plates)  through the passive components while the energy is dissipated as heat and/or light and/or other types of energy, depending on components.