Rolled 2, 13 = 15 (2d20)
>>5382398>>5382325>>5382301>>5382155>>5382082>>5382077>>5382046>>5381992>>5381975You advance towards the closing gate, following the retreating dwarves at a more leisurely pace. You beckon to the Throat-singer, and he falls in alongside you, still humming his eerie, vibrating song. The two fire-lizards trailing him, and Agno trailing them not long-after; Karz Throat-singer may summon them, even direct them, but he is not so skilled as the kobold at wrangling them and keeping them on ‘best behaviour’ when the magic ceases to flow.
Empowered and focused by the bardic music, you draw up mana from within. You speak the words of power, stride forward the requisite number of steps, move your hands in the forceful, purposeful movements necessary for the spell’s somatic component, and raise a <Wall of Stone> up from the very earth beneath the closing gate.
[DC 12, thanks to Karz's song and circumstance]